Schizophrenic Difficulty



""There were sequences really near the beginning that kicked my ass until I was wearing my buttocks like a hat, while the closest thing to a final boss fight is basically you versus a wheelchair-bound cross-eyed hobbit, and you're armed with the BFG 9000.""

- Zero Punctuation on Halo 3

This happens when a game has a difficulty curve that makes no sense. The game isn't always hard. It isn't always easy. It just can't seem to make up its mind. There are even portions that seem to be the perfect difficulty, but you never know when one will turn up. Maybe there's an element of the game design that does not work particularly well. Maybe the developers were trying to make the game feel realistic. Maybe they just had no clue what they were doing. Whatever the case, you've run into Schizophrenic Difficulty.

Often occurs when major elements of gameplay are left to the Random Number God. Random dungeon layouts can put important equipment on the bottom floor. Random stat growth can rob your tank of vital Hit Points. A Crutch Character or Exclusive Enemy Equipment that is only available on a few scattered levels can also make portions of the game much easier than others.

Compare Difficulty Spike or That One Level, when a single level is much harder than its preceding levels, and Breather Level which is its inverse. Also see Early Bird Boss, which can cause this in the early parts of RPGs and games with RPG elements.

Non Indicative Difficulty is an extreme case where, for example, playing on "Normal" is harder than playing on "Hard", at least in some way.

Action Game

 * The Wonderful End of the World (basically a PC indie version of Katamari Damacy) suffers from this. In some levels you'll collect enough stuff to get an A+ rank with a third of the timer remaining, while in others you'll scramble up to the last second and still only earn a B rank. The very first level is an example of the former, but one of the two levels it unlocks falls into the latter.
 * Battle City and somewhat its sequel Tank Force has this syndrome too. For an example, stages 20 and 34 in Battle City are the hardest ones in the game while stage 35 is a breather level.

Beat Em Up

 * Most of the levels of Altered Beast: Guardian of the Realms are a breeze (in contrast to the bosses) except for a few scattered levels that are intensely and inexplicably difficult (the hardest probably being the fifth). Difficult levels don't seem to get any more (or less) frequent as you near the end, either.
 * All the levels in Battletoads are hard, but not sequentially so. Level 3 has the racers, which are virtually impossible, while level 5 has the surfboards, which, while difficult, aren't as bad. In some levels, every obstacle is instant death, while in some other, later levels, all obstacles take one or two units of health.

Fighting Game

 * A lot of fighting games in general have random characters whose AI seems to vacillate between brilliant and stupid for no discernible reason. Some SNK Bosses even throw in an entire "stupid round" where attacks just seem to work and a "smart round" where they play a Perfect Play AI.
 * In Mortal Kombat 2, Jade was a secret boss, with the cheap AI that you might expect from a boss. In MK3, Jade was a selectable character, but the programmers never fixed her AI. Considering that it was almost entirely random when, or even if, you fought Jade in single player mode, she was a single-handed example of this trope.
 * Soul Blade's Edge Master Mode has several points where the challenge you have to accomplish is much harder than the one after it. Examples being those that require you to use a certain move (especially hit your opponent in the air), those that require you to defeat your opponent against a time limit or with limited health, and the Colosseum matches.
 * Tekken 2 has a point around Stage 5 where the difficult level suddenly hikes, especially if you are fighting against Law. Afer this it usually isn't too difficult. This is because the fifth level forms the mid-boss, even though at this stage it wasn't mentioned.
 * Guilty Gear XX's Story Mode is all over the place, ranging from "Beat me, please" to "I AM COMPUTERIZED FIGHTING PERFECTION AND WILL SHOW ALL PUNY HUMANS WHAT TORMENT AND SUFFERING IS" depending on which story arc you take.

First Person Shooter

 * Serious Sam - The First Encounter, most notably in harder difficulties. Last room in the third level raises the difficulty, then it goes down again. While Dunes is harder level, the following Suburbs and Sewers are Breather Levels. Metropolis, on the other hand raises the difficulty again a lot which won't let down until the end of Karnak and afterwards the difficulty starts to jump up and down very frequently.
 * So much of the game's difficulty comes from scattered War Sequences and other game design death traps that the series might as well be the trope codifier for "That One Part Of That One Level".
 * Star Trek Elite Force II. The difficulty yo-yos up and down the whole game, with a plague of Demonic Spiders near the beginning followed by a single, supposedly more fearsome specimen -- built up as a major Boss Fight -- who goes down almost instantly. Or compare the warp core level, where you have to shoot dozens of targets (without hitting the Destroyable Items!) within a merciless time limit, with the endgame, where there's a single monster you need to kill, a gun that can do so in a handful of shots, no time limit, and infinite health and ammo rechargers.
 * The final mission of Call of Duty 2, Crossing the Rhine, is much easier than the previous two brutally difficult missions (D-Day and Hill 400). The difficulty also drops from Stalingrad to Africa, then shoots back up for Caen and the aforementioned two missions.
 * The Halo games tend to be schizophrenic with their difficulty. For example, Halo 2: very hard->hard->medium->easy->hard->->medium->hard->medium->easy->ultra-hard->hard->medium->easy

Four X

 * In Civilization III, random map generation can make victory practically unattainable. Having no Iron or Copper means you're stuck using archers and longbowmen until gunpowder is invented. This, coupled with an aggressive enemy AI, can cause all sorts of pain for the player. On the other hand, you can get a "double gold riverside corn copper" start and then receive free technologies from huts, which makes the game a cakewalk.
 * You'll need extra luck if you don't have a source of oil in the late game; Riflemen seem to have a greater difficulty dealing with Tanks than Spearmen.
 * It's not much improved in Civilization IV although some units were added, like Mechanized Infantry, to help smooth out the differences between Iron/no Iron and especially Oil/no Oil. It's a lot easier to win a non-military victory in IV, though.

Hack And Slash

 * Diablo II: You sequentially pass through the three difficulty levels with your character as you level up (Normal for levels 1 to ~40, Nightmare until ~70, and Hell from then on). However, the actual difficulty of each is kinda messed up.
 * Normal can be tedious or very difficult depending on your build. Many characters are stuck with a pathetically weak attack as they wait for the higher level ones they actually want to put points into to open up.
 * Thankfully, many low-level skills now add bonuses to higher level ones, giving most builds at least one or two early places to dump points.
 * Nightmare is a complete joke- by now you have your strongest attacks maxed out, while enemies are only slightly stronger than in Normal.
 * Hell is true to its name. All enemies are completely invulnerable to at least one element, randomly spawned unique monsters gain 3 boss-modifiers (which can give them more elemental immunities), and your own elemental resistances are all dropped by one hundred.
 * A similar thing can be said about act bosses, where Schizophrenic Difficulty is mixed with Boss Dissonance. The first boss, Andariel, has quite an adequate low difficulty considering she's the first boss, but the second boss, Duriel, is one of the toughest enemies of the game. The third boss, Mephisto, is very easy, especially compared to his bodyguards, the High Council, who are AT LEAST as hard as Mephisto himself. Then, the fourth boss, Diablo, is clearly the toughest enemy of the game (which makes sense, considering he was originally the Final Boss prior to the expansion). By contrast, the added Final Boss in Lord of Destruction (Baal) is similar to Mephisto in being disappointingly easy compared to prior bosses and his "Minions of Destruction" that you are forced to defeat right before.

MMORPGs

 * World of Warcraft also falls prey to this trope - especially on PvP servers. Certain zones can be unplayable due to ganking and quest difficulty can frequently fluctuate depending on how enemies differ between areas.
 * Low-level players first encountering Gnomeregan may notice a surprising leap in difficulty compared to earlier dungeons.
 * Zones made before any of the expansions (Levels 1-60) are somewhat more difficult than higher-level zones introduced in the expansions (Levels 60-80). Quests are also usually more time consuming as well requiring Twenty Bear Asses rather then eight.
 * Cataclysm revamp made it even worse. Now, level 1-60 zones were revamped and are a very pleasant experience. 60-70 content is now the oldest and as such is missing a lot of new development ideas and is much more tedious than 1-60. 70-80 content ups the quality almost back to the new Cataclysm content. 80-85 levels have all the newest developments, but have vastly increased amount of experience needed per level and highest-level mobs are much tougher than previously. Tol Barad quests, accessible at 85 feature another jump up in difficulty.
 * Even once you finish leveling and start playing heroics, there's a significant difference across the different dungeons. Some people will jokingly call a free run while others will see people immediately quit in disgust.
 * During the open beta, Star Trek Online suffered from this, with the episodes and missions immediately following the tutorial being unreasonably (to the point of unplayable) difficult at times. By the time you got to level 11 where the difficulty was supposed to pick up, it actually dropped off some.

Platform Game

 * The Genesis Sonic the Hedgehog games are somewhat schizophrenic in their difficulty curves. In Sonic 1, Starlight Zone, the 5th one, is easier than its three predecessors. Chemical Plant Zone, while being the second in Sonic the Hedgehog 2, has a 2nd act that's more difficult than anything you face until Mystic Cave, the 6th zone. Sonic 3's Ice Cap Zone is easier than its three predecessors, and for obvious reasons, combining Sonic 3 and Sonic and Knuckles creates a two-hump difficulty curve. Sonic & Knuckles alone does, however, have a sensible difficulty curve.
 * The reason for Chemical Plant's difficulty is that it was originally intended as the 10th zone, back when the game was to include several scrapped levels. Conversely, the difficulty of Labyrinth Zone in Sonic 1 is averted as it was originally the second level in the game and moved to the fourth because it was too difficult.
 * Marble Zone is much harder than Green Hill Zone with its horrible amounts of lava and falling spikes. Conversely Spring Yard Zone is relatively more easy, apart from the BallHog enemy.
 * Sonic 2 for the Game Gear and Master System is horrible about this. Underground Zone, the game's first, is modestly challenging up until the boss, and even that is beatable with some practice. The next zone, Sky High, is more difficult than anything up until Scrambled Egg and Crystal Egg, the final two levels, due to unintuitive hang glider controls. Aqua Lake is back to being relatively easy, then bounces back to being Nintendo Hard with the second act. Green Hills (note the "s") isn't very hard at all until the third act. The game seems to make up its mind about its difficulty level starting with Gimmick Mountain.
 * Sonic Rush Series also does this. Especially as Blaze, since her level order is different to Sonic's.
 * Sonic the Hedgehog 2006 had difficulty all over the place in each of the main 3 campaigns.
 * Sonic the Hedgehog 4 starts off easy enough, before becoming quite hard from the second level onwards, mainly due to the broken level design.
 * Mickey Mania has 6 levels. The first, Steamboat Willy, is very easy. #2, The Mad Doctor, is likely the second most difficult level in the game (the difficulty jump between the first two levels is ridiculous). #3, Moose Hunters, is medium-hard, but quite short. #4, Lonesome Ghosts, is pretty hard. #5, Mickey & The Beanstalk, is about medium. And the final stage, The Prince & The Pauper, is quite merciless. It has five incredibly difficult segments to it (though the first isn't too bad), plus the final boss (who takes forever to kill and can mess you up if not careful).
 * Super Mario Sunshine has 10 difficult sub-levels peppered across the game where Mario loses FLUDD. After playing one or two of them, players will know that the cutscene of Mario losing FLUDD means a tough star ahead. A tough mandatory star in all 10 cases.
 * Scaler, a 3D platformer whose main draw was being relatively inexpensive, frequently alternated between being mind-numbingly easy and controller-crushingly hard. There is no lives system or penalty for death, and there are frequent unmarked/invisible check points that will respawn the player close to wherever he or she screws up, making it child's play to advance through the game. On top of that, most of the enemies, including the bosses, are extremely easy to kill. Most. Every so often the game will throw a Boss in Mook Clothing at you, and then there are the racing levels that are insanely hard to beat and are required to both progress through the game as well as for Hundred-Percent Completion.
 * The Lion King was of average difficulty, which equated to being relatively hard for a Disney game. Apart from certain levels, the most infamous being the second. How many people just stopped playing through the rest of the game just because of the ostrich ride? The gorilla sub boss caused a lot of angst as well, yet there were full bosses who collapsed after one hit.
 * Since all 20 levels in a world are unlocked and ready to play once you get to that world, Super Meat Boy either has a steady difficulty curve or this trope depending on whether you play the levels in order or not.
 * The difficulty can become even more uneven depending on when the player decides to do the Dark World levels, which are on par in difficulty with levels 2-3 worlds ahead of the current one. Players who tackle the Dark World immediately after their Light World counterpart will alternate between breezing through Light World stages and struggling through Dark World ones.
 * Frogger IS this trope. At least the Atari 2600 version anyway. Early on the difficulty levels change gradually from warmup level 1, slightly less easy warmup level 2, easy but noticably harder level 3, and then a sudden difficulty spike with moderately hard level 4. Then level 5 is easier. Then level 6 is legitimately hard. Then level 7 is a piece of cake, easier than level 3, only thing that makes it harder than rather than equal to level 2 is the fast moving snake on the log (which can be fairly easily avoided), then level 8 takes Nintendo Hard Up to Eleven with the close but slow moving traffic and fast moving water hazards. Then level 9 is a bit easier but still not cake. It goes on like this all game long.

Puzzle Game

 * Puzzle Quest Galactrix. Oh, boy, Puzzle Quest Galactrix. Specifically, the whole "fixing jumpgates" thing, which is not just schizophrenic, but positively hebephrenic (really obscure psychology joke).
 * Lemmings is all over the place, simply because when you know the solution to a level, it's hard to predict how difficult others will find it to discover. A perfect example is "Flow Control" from Oh No More Lemmings, midway through the last and supposedly hardest difficulty rating on the game. Depending on whom you ask, it's either worthy of that position or should have been in Tame.
 * Professor Layton had an amazingly twisted difficulty curve, which of course varies from person to person, seeing as it's a puzzle game (and people might have done some before). But some levels *coughchocolatecodecough* are consistently frustrating.

Real Time Strategy

 * The single-player campaign of Dawn of War: Soulstorm. The difficulty levels of each of the nine stronghold levels vary wildly with no way of knowing which ones are the hardest until you've already played through the game. The Ork and Dark Eldar strongholds are cakewalks (assuming you have enough Honor Guard to get past the initial zerg-rush/maze), the Space Marine, Eldar, and Necron strongholds are about average difficulty, the Sisters, Tau, and Chaos strongholds are hard, but doable, and the Imperial Guard stronghold is nigh-impossible for anyone who lacks a lightning-quick clicking finger.
 * This has a lot to do with the gimmicks the game employs at the strongholds and the schizophrenic rock paper scissors relationship that the different factions have to one another.
 * The campaign of Dawn of War II fluctuates up and down for its entirety, along with a huge spike with the Argus Gate mission, a huge drop after acquiring the Dreadnought and a sufficiently levelled Cyrus, a spike into the stratosphere with the two Bonus Bosses, and another drop with the relatively easy final mission complete with Anticlimax Boss. Chaos Rising, however, is far more consistent in its difficulty curve.
 * The online Tower Defense game Easter Island TD goes beyond this to chaotic difficulty. The same layout on the same level in different games can give wildly varying results. So much for keeping notes.
 * The levels in the original Populous were generated with an algorithm. A side effect was that there were some hard levels quite early in the game, a bunch of easy levels near the end, and the hardest level in the game was around the middle
 * UFO Aftershock borders on this trope and multiple difficulty spikes. First mutant mission is a cakewalk, but as soon as on third mission you can encounter very tough shotgun-wielding humanoid mutants (by that time you have only Alien laser weapons, which have pathetic range and damage) and fast sniper-ranged star like mutants, both of them can kill any of your unskilled soldiers with single critical hit. After you acquire shotguns for yourself it gets a bit easier. Another spike comes when Cultists come into play. On first mission against them you have to catch "real" cultists off guard on close range with your whole squad to bring them down without losses, mid range engagement is just a suicide. Second cultist mission is back to just difficult, because of captured equipment (especially weapon mods). When you get sniper rifles, scopes and trained Snipers, game goes from whatever difficulty it was to easy again. Then the Wargot show up, with their Mecha Mooks, powerful energy and kinetic weapons, and a love for incendiary explosives; all of which laugh at your armour at that point... on top of very good resistance to all non-armour piercing munitions. Fortunately that's offset by their humanoid nature (allowing snipers to make called shots). Later, the Starghost enemies raise difficulty again because they are either highly resistant (more resistant armour than anything before) nonhumanoid (preventing called shots) robots or actual ghosts (called Psionic projections) immune to your standard issue fully modded AP loaded XM8, MSG90 and dual MP5 forcing at least one of your (now Super)Soldiers to waste backpack space to carry an UltraSonicGun or other energy weaponry.
 * The first Age of Empires I game suffered from this. The Izumo campaign was the worst by far (the first two levels were extremely frustrating nomadic levels, pitting a laughably small force against an army), but the Babylonian campaign had shades of this as well.
 * Flash TD game Cursed Treasure - Don't Touch My Gems has a fairly balanced difficulty ramp. That is, until ninjas appear. With their first hit, they turn invisible, being unable to be targeted and making mid-air shots heading to them disappear. Then the ninja champions come out to play: More health (enough that the direct damage spell won't save you), twice as fast and still turning invisible, so by the time they become targetable again, they're often inside your base and you can only hope that your towers will activate the chance to cause fear. It's not uncommon for the last boss of the wave to be killed in seconds, but the entire level leading up to that to be laid out solely to deal with the ninja waves.
 * Command and Conquer Red Alert 3: Uprising's Commander's Challenge mode has this in spades. Many levels -- though not all of them -- have one or more "gimmicks" associated with them: one mission is Tanks Only, one features enemies that attack only with ninja, one gives you a set of powerful but immobile towers, etc. Depending on how well a given player's favored, practiced tactics work on a particular level, they can go from trivial to maddening and back again. Worse, the game unlocks new units with each mission, and the missions are largely nonlinear; two runs of the same mission can be wildly different in difficulty if you unlocked a particularly effective unit in the meantime.
 * The original Command and Conquer played with this in the GDI campaign. A commonly missed part of the plot has to do with the GDI being seriously under-funded. This leads to mid-game missions that are far more difficult than later ones due to the lack of starting money and adequate sources of tiberium to harvest. The lack of funding for most of the campaign actually forces GDI players to use subversive tactics--such as sneaking into bases to capture & sell expensive buildings--instead of the staple GDI tactics such as tank force steam-rolling.
 * A form of player-induced schizophrenic difficulty, League of Legends gives you four random teammates and pits you against five random enemies. This being a heavily team-based game, many (some would argue most) matches are decided by who gets the complete beginner or leaver on his team.

Rhythm Game

 * Guitar Hero World Tour. The setlists are made so that, instead of a linear progression like in previous games, you have a handful of setlists you can choose at any time. Fair enough, but that's not where the crazy difficulty comes in. The setlists themselves seem to have been spastically arranged. A fairly easy setlist with Spiderwebs and Eye of the Tiger has a fairly crazy Zakk Wylde Battle wich ends with Stillborn (which is fairly challenging), and another setlist has Sweet Home Alabama, which has a ridiculously hard solo, sandwiched between the far easier Are You Gonna Go My Way and Assassin. Pretty sure They Just Didn't Care.
 * Also, most band games are unavoidably like this when playing in a group. Even if the songs are ordered properly by band difficulty, one is probably going to be harder on guitar and another harder on drums, etc.
 * This as a common criticism of The Beatles: Rock Band, whose Story Mode tracklist is organized by release date instead of difficulty, meaning the difficulty varies wildly between songs: For example, some of the game's easiest guitar songs (Hello Goodbye and Getting Better) are just one or two tiers away from some of the hardest (Revolution, Birthday and Back In The USSR), while I Saw Her Standing There, quite possibly the hardest bass song in the game, is in the very first tier. At least the game tells you the song difficulty before you play and you can change between Easy, Normal, Hard, and Expert.
 * In Dance Dance Revolution X2 on the PS 2, boss songs are unlocked in this manner. The first song is Dance Dance Revolution, which isn't hard outside of its jumps, then right afterward comes Dead End (Groove Radar Special), which is absolutely loaded with Fake Difficulty, and has only one chart, which is an 18! After that comes Pluto The First, which is notorious for being one of the worst charts of all time and having even more Fake Difficulty than DEGRS. Once you've gotten past that, you'll find that the remaining two bosses, Kimono Princess and Roppongi Evolved to be very easy by comparison.
 * Rhythm Heaven on the DS, arguably. Two levels in the second set (Moai Doo-Wop and Rhythm Rally) are considered some of the hardest in the whole game. Sometimes you get a very hard level between two easy ones (Big Rock Finish), and some of the easiest ones are right before the end. YMMW on which levels are hard and which are easy, but most people agree that the difficulty is anything but gradually increasing.

Role Playing Game

 * This seems to happen a lot in both traditional RPGs and MMORPGs, in general. Earlier levels can actually be harder because your characters don't yet have many items or skills. Then, middle content can become a breeze once you've got your hands on some decent equipment and spells, only to find yourself butting heads with a enemy that forces you to get serious again. Finally, end game content can either be disappointingly easy, again as a result of having now acquired the best weapons and spells in the game, or mind-numbingly impossible, when all the awesome loot and cool powers in the game world mean nothing to your even more powerful enemies. Double this for any Linear Warriors, Quadratic Wizards situation.
 * Several reviews that describe The Last Remnant as painfully erratic in its difficulty, which leads to a lot of disappointing boss fights and cheap deaths. There's nothing quite like walking into an area and starting a normal fight with really high morale (suggesting you're a lot stronger than them and should have visited 'properly' when you were weaker) and then getting whipped by the boss.
 * The first Pokémon Mystery Dungeon games begin quite easy, then you face the three legendary birds when you aren't even Lv. 20, and Articuno is That One Boss. Afterwards, it becomes absurdly easy until you finish the story. Then you meet a Difficulty Spike in the next three dungeons (first one with much tougher enemies, the second goes heavy on traps and the thirs have pokémon that seem random, but have all kinds of Game Breaker properties). Then the difficulty plummets down for a while until you get to the ultimate dungeons.
 * Of course, this is all assuming your starters isn't a Grass type. Then you're boned.
 * Might and Magic IX had this, mainly because it was only half-finished as shipped and the resulting gameplay had some rather noticeable flaws. The first part of the game seemed more neglected than anything else, resulting in a "tutorial" stage that was punishingly difficult due mostly to a lack of any sort of preparation. Trying to follow the "main path" of the game past that point led through a somewhat stable difficulty curve, but any sort of deviation from where the game automatically expected you to go quickly led to the discovery of numerous side quests which could be completed without placing your team in any form of danger whatsoever, making the rest of the first half of the game ludicrously easy. The difficulty eventually spikes back up out of nowhere before bottoming out again, and varies depending largely on which promotion quests you decide to do.
 * From Jahara to Giruvegan storywise, Final Fantasy XII is all over the place.
 * Persona 4 starts with 2 extremely easy dungeons, then a Wake Up Call Dungeon followed by one of the hardest bosses in the game. The next dungeon is a good step harder than that and has possibly the HARDEST story boss (almost the only other boss you will actually need to grind against), then the next dungeon is easier, with a challenging but not hair pulling boss, the next dungeon is a little harder, with a boss nearly as hard as the 2 very hard early game bosses, then the next dungeon is easier, and the next dungeon... but the boss difficulty finally spikes.
 * Devil Survivor has this a little bit as well. Day 1 has a tutorial, followed by a nasty Wake Up Call Boss ten levels higher than you right after the tutorial, and you can't fuse demons until you beat him... and once you do beat him, your fusion makes short work of the demons for the rest of the day. Day 2 is only a little harder, till the end mission, which is an Escort Mission, and therefore automatically a big pain. Day 3 is pretty easy, except for the boss at the end who is That One Boss. Day 4 is a little harder, Day 5 is a mix of Scrappy Levels and Breather Levels, Day 6 is mostly pretty easy, and unless you choose Yuzu's route, Day 7 is an exercise in forced grinding.
 * The World Ends With You can be like this, thanks to its very complicated battle system. A hard boss battle might force you to learn how to use a gameplay mechanic you had been ignoring beforehand, and suddenly the rest of the game becomes easy until you run into another Difficulty Spike. Repeat until you get to the post-storyline content, which requires jumping back and forth between a bunch of Bonus Bosses while constantly switching your difficulty setting and HP around.
 * Final Fantasy IV for the DS had this in its dungeons. You expect, as you go through the levels of a dungeon, that as you progress the monsters will get harder the farther you get from the entrance. In many dungeons, though, this is reversed. The nastiest monster in the Tower of Zot, the Frostbeast, likes to hang around the entrance--and its Palette Swap upgrade, the Flamehound, is only found in the lowest levels of the Tower of Babil despite being a right nightmare. In the Sealed Cave, while the are everywhere, the Chimera Brain with its awful Blaze attack is most often found in the first half of the dungeon. The Very Definitely Final Dungeon appears to have a more standard difficulty curve, with Demonic Spiders of increasing levels of meanness populating the first several floors, then floors with only Boss in Mook Clothing (or Degraded Boss, depending on your perspective) encounters, and then, right before the Final Boss...ridiculously weak enemies. What the hell?
 * Earth Bound Zero has a bad case of this, mostly due to the high random encounter rate. At least, until Mt. Itoi, where it spikes to an insane level and stays there. The creator admitted that they didn't playtest it or try for any sort of balance; they just wanted to finish making the game.
 * Earthbound also has difficulty issues. It starts out fairly challenging, gets extremely easy after Happy Happy, gets hard when you reach the mines and stays hard all the way through Moonside, drops insanely low all the way through Scaraba, gets a bit more challenging in Deep Darkness, and finally gets pretty nasty once you reach Fire Spring through the end.
 * Dragon Quest VI has a pretty strange difficulty curve. The game's difficulty increases steadily until it gets Nintendo Hard at the Disc One Final Dungeon, after which you get access to the game's Character Class System. The game's difficulty then drops a bit after that, and once you start mastering the classes and then some secondary classes, the game becomes really easy. Then, all of a sudden, the enemies and bosses get all sorts of cheap attacks, and the game becomes even more Nintendo Hard than it was before.
 * Dragon Quest VII also does this with its own Dharma Temple event. The mini-dungeon and encounters surrounding the area are stupidly hard. This, however is a trick: If you are (and most likely will be) low level for this area, you can use the area for a Peninsula of Power Leveling once you actually get your Job Classes. But if you decide to grind out your levels before going to the temple, then you can't use the encounters there to gain job points.
 * While Lord of the Rings The Third Age mostly avoid this on the regular storyline, the Evil Mode is a massive case of this. Some early chapters are easy while others are ungodly hard. Chapter 6 is particular is horrible as you're facing The Fellowship itself, which are Purposefully Overpowered when in your control and still remain overpowered, making it a nightmare. Meanwhile Chapter 9 (The last one) is a joke, though it's justified as you use an Oliphaunt first, then the Witch-King and for the last match... Sauron (Or rather, The Eye of Sauron on his tower), so of course you're having it easy.
 * Microprose's Magic the Gathering game does this somewhat: If you don't have an easy way to kill the lower-life opponents, their aggro decks will walk all over you.
 * Valkyria Chronicles pretty much peaks early on in Chapter 7, an absolutley brutal Final Boss Preview, but gets much easier later on, when your troops have leveled up and learned how to actually hit things. Some classes get access to new weapon types at higher levels, the most notable being Flamethrowers for Shocktroopers, which let you One-Hit Kill enemies in cover and then take the cover for yourself, GREATLY simplifying the game. You also get Smoke Rounds for the Eidelweiss, a Machine Gun that fires 30 shots(when even 3 hitting the target's head is enough to kill) and Alicia  and becomes even more of a Game Breaker than she was before. Early chapters are near impossible to A-Rank without a New Game+, but play your cards right later on and you'll be getting A-Ranks left-right and centre and, apart from a few examples of That One Level and Guide Dang It, you're unlikely to have much trouble. It pretty much feels like you're an army of Quadratic Wizards facing an empire of Linear Warriors.

Shoot Em Up

 * Mushihime-sama Futari Black Label brings us God mode, which replaces version 1.5's Ultra. Stage 1 starts off already difficult, but Stage 2 somehow manages to be easier, thanks to the immense slowdown and the many, MANY opportunities to cancel bullets and rack up hundreds of millions of points. Then the game goes back to being very Nintendo Hard with the Stage 2 boss.
 * The Touhou photography games, Shoot The Bullet and Double Spoiler. The games are broken into level, which are themselves broken into scenes. You unlock levels by either clearing a certain number of scenes from the preceding level or a certain number of scenes total. Anyway, the difficulty of both the scenes within a level and between the levels themselves can be fairly random. For instance, the first level of Shoot The Bullet is mostly trivial, except for the very last scene, which is probably worse than anything in level 2. And Double Spoiler has level 11, which is markedly easier than the previous three levels.
 * Space Invaders Infinity Gene has a Challenge mode that basically randomly generates levels. This leads to randomness in the difficulty. Also, one of the bosses has an intro that lasts minutes before it can be attacked, and this boss may appear randomly at the end of any Challenge level.

Simulation Game

 * Descent 2 had Schizophrenic Difficulty, with many spikes and troughs along the gently rising slope. In some sections the robots could be picked off with ease, yet just around the corner one false move would see a phalanx of murderous mechs erupt from the floors and walls, firing blinding flares and flooding your lines of retreat with bouncing shots... It didn't seem to make for a bad game, though, since it was enjoyably unpredictable, but only rarely Nintendo Hard.
 * Harvest Moon: Frantic Farming has this; mainly either when your opponent was the Witch Princess or a team battle near level 6 or 7. The former was a tough, but fair battle no matter which level you fought her on. The latter achieves it's difficulty spike due to your CPU partner suddenly becoming near-useless, leaving you in a virtual handicap match against the CPU team.

Third Person Shooter

 * Red Faction: Guerrilla. Some main missions are laughably easy, some are hair-tearing hard. And normally the game is damn hard too, but not always.
 * Red Dead Revolver had some levels that were too easy, some that were just right and incredibly fun and some that caused many a player to throw the controller across the room in frustration.
 * Arguably several missions in the "Rise of the Empire" campaign of Star Wars Battlefront II. In general, the campaign isn't very difficult, but some missions (A Line in the Sand, Knightfall, Tying Up Loose Ends, etc.) are unusually difficult, others are fairly easy, and in short, no two levels have the same diffiulty.
 * The first half of survival horror game Cold Fear has lots of tight corridors, a dash of Camera Screw, and takes place on a small whaling ship rocking back and forth in a storm, making it impossible to walk in a straight line, much less shoot with any accuracy. The second half has much more powerful enemies, but disposes with all the things that made the first half so challenging.

Turn Based Strategy

 * Most of the Advance Wars games suffer from this with the difficulty peaking anywhere but the final boss fight and lots of late levels being total cakewalks. It depends on strategy.
 * While otherwise a very good game, Final Fantasy Tactics suffered from this. The first few battles are easy (though the second battle can be hard if you opt for the more difficult win condition), the 4th battle is extremely hard, the 5th battle is easy, the 6th and 7th battles are somewhat challenging, the 8th battle is easy, the end chapter battle is hard if you don't figure out a specific strategy, then the first half of chapter 2 is easy, mixed with a few randomly hard battles. Chapter 3 throws out battles of varying difficulties though easier than the hardest battles in chapter 2, then suddenly has a sequence of 4 battles, 2 easy, 2 of some of the most obnoxious Scrappy Levels in any videogame ever (a 1 on 1 fight against That One Boss and an Escort Misson, with the weakest, stupidest, most suicidal escort EVER). Chapter 4 starts likes Chapter 3 but a bit easier, then gives you a Game Breaker character who kills the remaining difficulty of the game.
 * Of course, if you grind for high level jobs, say, the Ninja, the Dancer, or if you really wanna take the fun out the game, the Calculator, this game difficult curve becomes flat as a pancake. Granted, the escort missions are still going to be a pain in the butt, but that's nothing a crack team of Blade Grasping, Move+3 ninjas can't solve.
 * Final Fantasy Tactics Advance has an abnormally difficult early game, due to a combination of mediocre starting units and a lack of chances for Level Grinding. Once the Random Encounters start showing up on the map, though, there is absolutely nothing stopping you from scooping up every last Game Breaker available, until the final boss's ridiculously powerful magic is the only thing that can actually stop you.
 * Justified but still very much present in Fire Emblem Radiant Dawn (10). It starts with a particularly Ragtag Bunch of Misfits trying to sneak their way past the forces of the most powerful army in the game, making it significantly harder than later parts where the threats are still great, but the player is controlling stronger armies. this is more jarring for players who didn't play the preceding game Path Of Radiance, which, unlike Dawn, has a learning curve. Also, the end of most Fire Emblem games (especially Dawn) can range from "not too bad" to "basically impossible" based on how well the best fighters and items were managed leading up to it.
 * The end of Radiant Dawn is only as hard as you want it, which is what makes it so jarring. You've spent the game raising up almost 70 different characters, and you're only allowed...what, 18 or so? What's more, you're given a crapton of Game Breaker units that could solo the ENTIRE Endgame by themselves, plus two units that can, in exchange for extreme efficiency sacrifice and LOTS of Level Grinding and patience, make the 3rd part of the Endgame, considered by many to be pretty much the hardest chapter of the endgame, into an ABSOLUTE joke. Oh, if trained and used Micaiah, you'll find she can attack the Final Boss without retaliation, but you probably won't know this because you'll be afraid your "Lord" character will die from the Boss's ridiculous magic, even if Micaiah is a mage. The same goes if you did That One Sidequest to unlock, who comes with the most powerful staff in the game (which heals every single one of your units in the field), but only joins for the LAST level, but can use ALL staves, Light and Dark Magic, can double attack the final boss (something which is very hard to achieve), and ALSO won't face retaliation.
 * In short, the difficulty of Radiant Dawn is, in order from hardest to easiest (by Part): Part I > Part IV > Part III > Part II > Part IV Endgame. Yep.

Wide Open Sandbox

 * In Dead Rising, the combination of the mall layout and the time constraints can make one mission incredibly hard and the next incredibly easy. Rescue from the hardware store? Piece of Cake! Rescuing people from the toy store? Not so much. In addition, whether or not you've fought various optional psychopaths will also influence your difficulty, particularly if you've killed Adam and looted his miniature chainsaws.
 * The sequel is better about this (mostly because your escortees are markedly less retarded), but the psychopath fights are still all over the shop.
 * Anything Grand Theft Auto - some missions are so easy they could be accomplished by a five-year-old (not that they should, mind you), while others are so frustratingly hard that you'll probably want to either break your TV, your controller, or both.
 * Prototype averts this pretty well. For instance, the beginning levels have "cutscenes" panning the camera to hard-hitting military hardware available for grabs just before a critical sequence requiring high damage output from you, being that the player's under-developed state of power at that point makes self-reliant tactics more(read: unnecessarily) challenging. The later levels give you alternatives(some levels actually removing them) in fighting options, but do little to immensely swing things in your favor.
 * Even then, the first visit inside a military base pits the player against a fight that compares with a much, much later military base fight with one of the game's more notorious enemies.
 * That's assuming both examples involve all available upgrades purchased.
 * Some events unlocked late in the game tends to be disproportionately easy, while some early events available can still pose quite a challenge even after visiting them late-game with substantial character upgrades.
 * A lot of the game, especially the Kill events, are designed to be played in a certain manner or centered around a key strategy that may or may not be apparent. This means that any given mission or event can seem disproportionately easy or hard should you not adhere to it.
 * Certain consume and base infiltration events become harder later in the game, even if they're flagged as easy, mostly due to the fact that the fast-detecting UA Vs will just about always thwart an attempt to get into a base steathily, then the difficulty drops drastically once you're inside the base proper and there are no more detectors.
 * Randomly generated missions in X3: Terran Conflict' are assigned a "Difficulty" ranking. The difficulty just seems to indicate how likely you'll get raped by a M8 class bomber. At high combat ranks (gained slowly by killing enemies), an "Easy" mission will spawn multiple battleships in patrol missions -- regardless of what sort of ships you own. Good luck killing those battleships in your piddly little corvette!
 * In-Sector versus Out-Of-Sector combat. To save on processing power, OOS reduces combat to ships taking turns firing a single, point-blank volley from all guns at once at a single target. All other variables (area-of-effect, weapons recharge, and so on) are taken out of the equation. This skews combat in favor of Wave Motion Guns to the point where recommended loadouts are often drastically different for IS and OOS.
 * OOS is also skewed in favor of weight of numbers, to the point where a mob of Jaguar scoutships can kill a Python destroyer with about 20% casualties, something that Artificial Stupidity makes impossible IS.

Puzzle Games

 * Sudoku puzzles generated by a computer. While they are solvable, the difficulty is all over the place since there's no easy way to quantify "difficulty" in a puzzle game.
 * Other computer generated puzzles suffer from this as well.
 * Amazingly, five-in-one sudoku puzzles tend to be easier. This makes no sense to a beginning player.

Real Life

 * The English textbooks used in Japanese primary schools differ radically in difficulty from lesson to lesson, with one chapter teaching just one short phrase and a handful of words which most students will already know, and another lesson teaching sixteen different phrasal vocabulary items while at the same time trying to teach numbers up to sixty, which is already difficult in and of itself. For comparison, the same grammar point in the junior high school curriculum is taught with around seven items, and most SLA research suggests that even for older students, a maximum of 8-10 vocabulary items should be taught in any given lesson. The lessons are not ordered from easiest to difficult and often a really tough lesson comes on the heels of a pointlessly easy one or vice versa.
 * But this may be a subversion because children and young teens learn foreign languages easier than older teens and adults do. That's why they tell you to learn a language as early as possible.