Stalked by the Bell

Most video games strongly enforce their time limits -- if the clock reaches zero, death immediately follows.

But some video games like to make their punishments a bit more interactive. A classic example is deploying an Invincible Minor Minion (Touch of Death optional) to chase the player while they still try to complete their objective, but other forms can include Malevolent Architecture (like an Advancing Wall of Doom).

This is most prevalent in Arcade Games, as a deterrent to discourage one player from hogging the machine if others are waiting in line behind them.

Note that this is not the same as levels that incorporate an Advancing Wall of Doom (Descending Ceiling, rising lava, etc.) from the start of a level, or a battle against an Advancing Boss of Doom, or any other predefined segment; when a player is Stalked by the Bell, the threat only manifests as a punishment for not completing their objectives before the clock expires.

Likewise, this is not merely a Timed Mission justified by an in-universe threat, as many missions are already justified by a Self-Destruct Mechanism, Incredibly Obvious Bomb, etc.

Action Adventure

 * In the original Rygar, time running out would cause the entire background to go black and a huge, invincible wraithlike monster to fly at you from the left. Interestingly enough, it not only was possible to evade this monster, but repeatedly; the real danger was not getting killed by it or the monsters normally a part of the level.
 * In Terraria, taking too long to battle certain bosses will cause them to become invincible and kill you with one hit.
 * In The Legend of Zelda Skyward Sword, you must enter "Silent Realms" to collect tears at one point, in order to progress. These tears also extend a timer, and when that timer runs out, you get chased by the realm's guardians - who can kill you in one hit. With some pretty badass music too.

Action Game

 * Take too long to kill the enemies in a level of Joust, and an "unbeatable?" pterodactyl will appear and try to kill you. It's not completely invincible, but the window to kill it is so small as to be nearly non-existent.
 * Early versions of this game even had a bug where the path it took let the player stand on a ledge and kill a continuous stream of them.
 * Wolverine: Adamantium Rage for the SNES released Elsie Dee (an android filled with plastique and modeled after a child) if you took too long. She crawled all over the level to chase you down. If she managed to touch you, you'd get a Nonstandard Game Over as she, Wolvie, and the stage you were in exploded.
 * Qix sent out two extra sparks which were able to travel up partly completed lines, unlike the normal sparks. And if you stay in place too long, a fuse starts burning up the line.
 * In Dubbelmoral!, if the kid stays out too long, his mom comes after him, batting eggs? at him with a Frying Pan of Doom.
 * In Mappy, the first warning to hurry up adds more and faster Meowkies to the stage, and some time after that the invincible Gosenzo appears to chase Mappy.
 * In Shamus, if you don't clear out a room fast enough, a creepy sound would occur, then the Shadow would jump in after you from the corner of the screen. The Shadow can go through walls, can't be killed (only stunned), and is faster than the player. Good luck.
 * In Smash TV, if you loitered in a cleared room for too long after killing all the enemies in it, spinning disks of death would enter the room and kill you if you didn't make a hasty exit.

Adventure Game

 * In the Flash browser game Lucky Tower, shortly after discovering an adorable tame fox and deciding to take him home with you, a bizarre imp-creature first eats your adorable familiar, then begins to chase after you. If you dawdle too much with trying to figure out how to get rid of him, he eats you too.

Beat'Em Up

 * In the arcade game based on The Simpsons, Homer, Marge, Bart and Lisa get flicked by a giant hand if they stay on one screen too long.
 * Splatterhouse 3 often had either your wife or son trapped in some room at the far side of the level where you started and a timer counting down, along with periodic cutscene reminders that they were in peril from the boss monster in that room. If you failed to reach the room in time they would already be dead when you arrive to fight the boss, which didn't end the game but would change the ending you would receive when you complete the game.
 * Death also shows up in Grabbed by the Ghoulies by Rareware. If you fail a challenge (say, run out of time), the Grim Reaper will show up and chase Cooper around, destroying everything in his path.

Driving Game

 * In Zone Raiders, a massive flying battleship would attack if the timer reached zero. The timer would freeze whenever the player was out of detection range; which meant no live enemies or stationary detectors in the area.

Edutainment Game

 * Think Quick! also used a dragon to enforce the time limit; this dragon was actually the game's Big Bad.

First-Person Shooter

 * Resident Evil Survivor 2 sends Nemesis in to chase and kill you once the timer runs out. Since he's invulnerable to your weapons and can kill you in one hit, this is a good sign that it's time to leave.

Maze Game

 * Bomberman: The enemies the timeout spawns aren't invincible, but until you gather up the right power ups, they're still far too numerous and fast for you to defeat or evade. They're deadly at low levels, but by level 30 they're an annoyance at worst.
 * The Tower of Druaga was especially sadistic. When the timer ran out, invincible Will-o-the-Wisps traced the walls in varying speeds. Also, the timer resets to 60 seconds. If Gil is still alive and in the maze when the timer hits 0, Gil dies instantly. This is just one aspect of this game that makes it hair-tearingly difficult.

MMORPGs

 * In the Fight Pits minigame in Runescape, if people spend too much time fighting each other, eventually some monsters from the other Tzhaar minigame start appearing in packs. First some weak ones, but if the players kill them then eventually more and more higher leveled monsters will appear until they kill all the players.
 * Graveyards in Spiral Knights spawn Phantoms a few minutes after entering the level. They're fast, tough, annoying, and can only be temporarily killed.

Platform Game

 * The Bubble Bobble video games have (up to two) Baron von Blubba/Skel-Monsta, an invincible whale skull which chases the protagonists when they cannot defeat all of the enemies in a level.
 * The secret rooms also had their own version, Rascal/Rubblen.
 * Up to 4, if you were playing Bubble Bobble Plus on Wii Ware.
 * Sue the Ghost Monster darts into Pac-Man in the platformer Pac-Land if he doesn't reach the goal in time.
 * Donkey Kong 64 had a disembodied voice shout "Get out!", followed by a crosshair appearing over the player.
 * The crosshair itself is always timed, but in some instances the crosshair appears because the player stepped into a spotlight or did something else wrong. When it appears then, its timer has one second on it. Better hope you're right next to the door.
 * Running out of time in NiGHTS Into Dreams caused the character to lose the ability to turn into Nights and revert to a kid. After which they were literally stalked by a bell in the form of a malevolent moving alarm clock in an egg. The sequel features ghostly creatures called "Awakers" who are a little more lenient: you don't lose until three latch onto you, and you can shake them off by turning into Ni GHTS.
 * In the SNK Neo Geo game Magician Lord, a demon would appear and proceed to kill you if you fooled around and let the time run out. It would home in on you, passing through walls if necessary, and would remain there until the level ended - meaning that when you died, you would likely respawn on top of it and die again, only able to make it a few steps each life until you found the exit.
 * Falling too far behind Metal Sonic in Sonic CD's race results in Dr. Robotnik killing Sonic instantly with a powerful laser, even if you have Rings on you.
 * In Sandopolis Zone Act 2, from Sonic 3 and Knuckles, if you let the lights go out (rather than keeping them on by periodically pulling switches scattered around the level), ghosts will appear one by one at set intervals. If three appear, they grow horns and start flying at you.
 * In Knuckles Chaotix, Metal Sonic will appear and attack you if you waste too much time just standing there.
 * Yoshi's Island. Kamek's minions swoop down on Baby Mario when the timer reaches zero.
 * After hearing Baby Mario wail while the counter mercilessly ticks down, the "Game Over" screen is not more suffering, it's a relief.
 * The Gameboy platformer Sneaky Snakes will have a flying axe appear when time runs out, which will stalk you until it manages to kill you.
 * 8-bit classic The New Zealand Story (or Kiwi Kraze, depending where you live) had an invisible timer in levels; if you took too long, the music changed to a frantic piece, giving you about 20 more seconds to finish the level before the music turned even more desperate, and a reaper floated onscreen, haunting you through the level and chasing you down, killing you instantly when it caught up to you.
 * 2 minutes into a game of Spelunky, the music will slow down and pitch bend to gain a spooky quality; 30 seconds later, the ghost will appear on the edge of the screen and hone in on your location relentlessly. It is possible to move around him if you have a wide enough space but he can't be killed and is instant death for you.
 * Instant Death AND being turned into a skeleton.
 * On the other hand, any gems the ghost passes through turn into highly valuable diamonds. An experienced player can take advantage of this for insanely high scores on every level.
 * Spend too much time on a screen in Montezuma's Revenge, and a bat will swoop down and grab you while a heart-stopping tune of horror plays from the speakers.
 * Cadash had an invincible floating skull (Taito had a thing for these, it seems) that did a massive amount of damage per hit. Interestingly enough, it was possible to buy more time, which would make it go away, although if the game ever reached that point it was pretty much just delaying the inevitable.
 * Athena actually has two different types of Invincible Minor Minion that will send powerful attacks in Athena's direction if she lingers too long on one screen.

Real Time Strategy

 * This is a major theme of the old PC RTS game Outpost 2. The plot of the planet involved gathering up enough resources to escape from your planet after a terraforming experiment goes horribly wrong. True to form, taking too long on any given mission would lead to the the player hearing "WARNING: The Blight is approaching!" and having scant minutes left, if that, to finish the map before their colony is consumed and destroyed by Grey Goo nanomachines.

Roguelike

 * Multiple Grim Reapers hunt you down if you take too long in a level of Chocobo's Dungeon. They're stronger than the boss of the game, and if you somehow "kill" one, another takes his place.

Role Playing Game

 * While there is no on-screen timer, if you spend too long in a given room in level 2-4 of Super Paper Mario you will be attacked by the invincible True Mimi.
 * Looking for gold Shadows or treasures in Persona 3? Beware of Death himself if you take too long...
 * Doubles if the Voice with an Internet Connection Mission Control states that the floor has no enemies, more enemies, or rarely still, all enemies as gold Shadows. The time limit is invisible, but in those cases, it will take half, nay, quarter the usual time limit until Death spawns.
 * Also, drawing a tainted card in a Shuffle Time will reduce the timer faster.
 * Luckily, Death is easily escapable, and for higher-leveled parties, beatable. Because Atlus loves to make you suffer, in fact, one of Elizabeth's requests requires you to kill the Reaper. (If you know how to use Armageddon, this can be done without fret; otherwise, steel thyself.)
 * Recettear has powerful enemies which spawn if you linger on one floor of a dungeon for too long.
 * In Final Fantasy XII your time at the Barheim Passage can become really nasty if you don't keep the lights on

Shoot'Em Up

 * Berzerk has Evil Otto electrocuting lollygagging players... and occasionally his own minions. Oops.
 * Otto has actually been responsible for at least two fatal heart attacks of players.
 * The sequel, Frenzy, let the player take down Evil Otto with three shots, but he would come back faster and faster each time he was vaporized. Eventually he becomes so quick that you'll only be able to pump one shot into him before he bounces all over your sorry corpse. Heaven help you if you try to blast Evil Otto when his father's around! His smiling face contorts into an enraged grimace, and he sends a swarm of Ottos after you to make sure you're good and dead.
 * In Star Control 2, if you fail to win the game by the end of 2159, the unbeatable Kohr-Ah war fleet will mobilize and start attacking everyone. After the last aliens are made extinct, the fleet will obliterate planet Earth, and then come after you personally. Some players intentionally let this happen partway, because picking the Plot Coupons off of a torched planet is easier than doing a miniquest for the aliens who normally inhabit it.
 * In the arcade version of Sunset Riders, if you stay still at the same area a long period a vulture will fly down to attack your character.
 * In Exolon if you spend too much time on a screen, an indestructible missile will be fired on you. It can be dodged by teleporting or jumping downward, but another one is launched afterward.
 * Sega's 1986 space shooter Quartet had, of all things, the Grim Reaper appear and slash you if you took too long on a level (thankfully doing the same damage as any other hit).
 * Sega's Spider-Man arcade game has two such menaces, a black-clad flunky in the fighting stages and a revolving spark thrower in the shooting stages, both of which did incredible damage and went away after killing you or after someone else joined in. Curiously, like Quartet, the player's vitality continuously drops no matter what, so this seems like overkill.
 * If you progress a certain amount without dying in in Gradius II and up, the game summons an invincible Option Hunter to steal your attack drones.
 * In the arcade version of Super Contra, if the player stays too long in the same spot to milk points from enemy grunts, a fireball will materialize from out of nowhere and instantly kill the player.
 * In the arcade version of Rush N Attack (aka Green Beret), a bomber will fly by and drop a bomb on the player if he stays too long in the same place.

Sports Game

 * The Atari arcade game 720 Degrees had a persistent swarm of bees that would show up if you took too long in getting into a skate park, and get faster the longer you evade them, thus they will eventually catch you unless you enter a park. "SKATE OR DIE!"
 * The bees come from an earlier Atari game, Paperboy.
 * And from the even earlier game Crystal Castles.
 * Honorable mention to Fruity Frank, where the enemy was only almost invincible And it was more of a boss than a "minor minion": The dreaded Strawberry.

Survival Horror

 * If you stand around too long in any room in Fatal Frame, a ghost will appear which like any other ghost in the game has a lethal touch. Only likely to occur if you leave the game unpaused, though.

Board Games

 * The Dungeons and Dragons board game "Dragon Strike" had a ridiculously powerful dragon who would show up if the players a) took too long or b) protected themselves.

Live-Action TV

 * A Game Show example: Run for Money Tousouchuu (the original Japanese version of Cha$e) often closes off a section of the play field midway through the game. Sometimes, instead of immediate disqualification for not vacating the area in time, the penalty is getting locked in the closed area while they release a hundred Hunters into it.

Adventure Game

 * The Nintendo DS game Hotel Dusk: Room 215 has a variant with a particular puzzle where

Beat'Em Up

 * In Express Raiders, if you stay on a train car too long, a Cartoon Bomb is planted on the coupling and explodes after a few seconds, disconnecting you from the rest of the train.

Edutainment Game

 * In Math Man (no relation to the Square One TV Show Within a Show), once the bucket reaches the top of the screen, it floods with paint and drowns the titular player character.

Platform Game

 * The original Mario Bros has fireballs developing and sweeping rows with greater frequency per level (though it does have a Donkey Kong-like hard time limit...)
 * In Kirby's Adventure, the first Nightmare battle features Kirby and the Nightmare Orb falling to some surface. If the player takes too long, the Nightmare Orb will fly off, and Kirby will crash into the ground and die. More accurately, gets crushed between the ground and upper part of the screen.
 * The boss of Spring Yard Zone in the original Sonic the Hedgehog will periodically swoop down to grab a block from the bridge that Sonic is standing on. If the player takes too long, he will have nowhere to stand. Similarly, the Sandopolis Zone boss from the aforementioned Sonic & Knuckles slowly walks towards a wall on the side of the arena, squishing the player if he doesn't destroy the machine quickly enough.
 * If you take too long during the final boss battle in Yoshi's Island, the floor underneath you will cease to exist.
 * The Stage of Gobi's Valley in the Pyramid Maze of King Sandybuts Tomb in Banjo-Kazooie requires a player to make it to the end in a time limit. If you fail the pyramid ceiling will come and crush you.
 * Both the "Puzzle Plank" and "Rolling Masterpiece Galaxies" from Super Mario Galaxy 2 feature planets that actually get cut apart by circular saws, causing you to fall to your death if you stay on them too long.

Puzzle Game

 * In Gussun Oyoyo, water will begin to slowly rise after a while. There is a powerup that causes the water to go away, but only temporarily.

Shoot'Em Up

 * While most of the Touhou series is shmups (and the fighting games do not have time), the first game, Highly Responsive to Prayers, is more a Breakout-type game with time. Failing to destroy all the cards on the level within the time limit will send waves of random bullets. Later games in the series behave differently: see the Miscellaneous section for more info.
 * In Air Fortress, the fortress itself will explode and kill you if you don't find your ship and escape in time after destroying the Power Reactor in the fortress.

Turn Based Tactics

 * Worms has its "sudden death" stage, where the entire map slowly sinks into the water (which wouldn't work if the Worms didn't have Super Drowning Skills).
 * So did Rainbow Islands.
 * And Bomberman 64's every-man-for-himself multiplayer mode.
 * Bomberman 64's multiplayer had different hurry-ups depending on the level. Some of them closed in the walls until players had no where to run from each other. Another just started dropping meteors on the players until they eventually died.
 * Also, generally speaking, Bomberman's hurry up tactic is to drop blocks around the play area to box players in and eventually squash them if a victor isn't decided.
 * Hedgewars follow.

Live-Action TV

 * Game Show example: In DERO! (as well as its Spiritual Successor TORE!), the Key Box Challenge portion of the Wall Room round is played in a corridor with padded walls. When time runs out, the walls close together to trap the player in between the pads. The player only fails the game if he/she gets stuck between the pads; if they complete the challenge a split-second after time expires and still manage to reach the Safety Zone at the end of the corridor without getting trapped, their attempt is still ruled a success (and this has in fact happened on the show).

Action Adventure

 * The Legend of Zelda LCD Watch & Game (No, not the other way around) would punish you if you stayed in a cleared room too long. Once you have the key to leave the room, after awhile your hearts would start to deplete.

Action Game

 * In Scurge: Hive, once your "infection level" time limit runs out, you start losing health. If you die this way the camera sticks around long enough to see the character metamorphose into a grotesque Scurge monster before breaking down.
 * If you don't defeat all of the enemies in a room in Quinty (known in the U.S. as Mendel Palace), those that are still alive turn red and attack you more tenaciously, getting progressively faster the more time you waste. For instance, the "swimmer" dolls will stop swimming and walk upright toward you, while the "copycat" dolls are no longer bound by mimicking your actions, and will fight you on their own. A few levels, such as the Sumo level and the aforementioned Enemy Mime level give you Musical Spoilers.
 * In Demon Sword for the NES, if you lollygag (stay in the same general area) too long, packs of "Demon Wolves" will start spawning and hound you to death.
 * The Devil May Cry games feature a Harder Than Hard difficulty featuring areas where you have to kill all the mooks within a time limit, or they'll activate their devil triggers.

Adventure Game

 * In a rare non-action example, Infocom's Planetfall kills the player after 8 full days of game time. It's hard to encounter this unless you're deliberately dragging your feet, however.
 * This happens in a more indirect manner in Stationfall: there simply isn't enough food around to last you more than a few days, as the food dispensers seem to be more interested in killing you.
 * If you manage to ration your food long enough to last four days the station explodes anyway.
 * Adventure game Future Wars, which is amazing since the game is about time travel.
 * Most people don't know this, but the original Leisure Suit Larry had a rather lengthy time limit of several hours, at the end of which, the sun would rise, and Larry would commit suicide out of shame that he hadn't lost his virginity yet. Note that neither the hooker from the bar nor the girl from the disco count towards this, only the final girl in the game does.
 * Likewise, King's Quest IV has a time limit of 24 hours, as stated in the intro. King's Quest III has an approximate 20-minute time limit between seeing the oracle and leaving on the ship, which is not stated in the game. King's Quest V has a variety of arbitrary death timers.
 * Space Quest I and II have a variety of self-destruction timers, with obvious results.
 * Quest for Glory II runs on a time limit: when it expires, a huge elemental will destroy the city of Shapeir. In the endgame, instead, the Sealed Evil in a Can will destroy the world.
 * In Pathways into Darkness, the Eldritch Abomination awakens and destroys the world after five days.
 * Tiny Toon Adventures: Buster and the Beanstalk sends Buster and Plucky on a search for three keys (made of three pieces each); while they have plenty of time to accomplish this, they're being hunted by Elmyra, and if they take too long in finding a piece, guess who appears out of nowhere to lock them up? (You're given a warning before this happens, but you probably won't want it.)
 * In Shadow of Memories (known as Shadow of Destiny in America), Eike will be killed in some way once the in-game clock reaches a certain time (which varies depending on the chapter). The whole point of the game is to go back in time to find a way to prevent your death. If you reach the "fated hour", two things can happen: in the present, you see a cutscene of Eike being killed, and then you get warped to Homunculus's place, who chastises you and gives you a hint on how to avoid death, before sending you back to the beginning of the chapter. However, if the time in the present reaches the fated hour while Eike is in the past (since time still passes in the present even when Eike isn't), you see Eike convulse strangely, and then literally fade from existence, resulting in a Game Over.

Beat'Em Up

 * It was discovered in a Let's Play that if you spend five minutes on a level of the arcade version of Teenage Mutant Ninja Turtles the Arcade Game without dying, an insta-kill bomb would drop on your head. (The Commodore 64 port would throw attacks at the player's character if he lingered too long in a completed level.)

Driving Game

 * Many racing games have the player's car coast and decelerate into a stop when the timer hits zero.
 * In most games like this, you can get a time extension and keep racing if you can coast your way to the checkpoint.
 * Unless it is an arcade version, where the arcade wants your money. It could even be a game where you are not actually racing against anyone and just trying to get to a finish line, but even if you are going 200 mph one foot from a time-giving checkpoint and run out of time, you're screwed.
 * Most older arcade racing games (OutRun, Daytona USA, etc.) are like that; most newer racing games use a much more lenient time limit to end the games of idlers or people who prematurely stop playing.
 * The player car in Rally-X games halves its speed and loses the smoke-screen ability when the player runs out of gas.
 * In Crazy Taxi, if you don't get a customer to his or her destination on time, the customer will get out of the taxi while it's still moving.

Fighting Game

 * In Super Smash Bros. Melee, if a Sudden Death fight drags on for too long, bob-ombs begin to rain from the sky.
 * Similarly done in Power Stone 2. If a match takes too long, giant meteors rain from the sky and crash into the players, reducing their health to just a mere silver. This makes one hit, even the weakest punch, become an instant kill. However, if players take too long to kill each other in this sudden death, more meteors fall from the sky and kills all the remaining players simultaneously, ending the match in a draw. Likewise, taking too long to kill one of the two bosses in adventure mode causes the boss to unleash a super attack that kills the player instantly.

First-Person Shooter

 * Team Fortress 2 either calls a stalemate if the timer runs out or has a sudden death mode where respawn (and class change) is disabled, and either team can win by killing all enemies. The timer is slightly more flexible in this game though, as "Overtime" kicks in if the timer runs out but any point is currently contested or one of the intels isn't at its point.
 * Call of Duty: Arcade Mode in Modern Warfare adds a timer and a life limit. good luck on Veteran.
 * Descent. The objective of each level (other than boss levels) is to blow up the reactor. Doing so activates the self-destruct sequence, and you have less than a minute to get out of dodge. This is hampered by seismic shocks.
 * Deus Ex Human Revolution follows the prologue with a hostage situation at a Sarif facility. Jensen is told to hurry; take your time, and the hostages will be dead before you even arrive.

MMORPGs
"Algalon: Farewell, mortals. Your bravery is admirable, for such flawed creatures. You are... out of time. *disappears*"
 * In World of Warcraft, many raid bosses go into an Unstoppable Rage if you don't defeat them within a set time limit, pretty much guaranteeing a Party Wipe. It's sometimes possible to kill them anyway in the few seconds left before you get demolished. Some bosses use infinitely spawning hordes of Mooks or stacking damage increases to achieve the same effect - sooner or later you get overwhelmed.
 * One particularly interesting way to achieve this effect is to have the boss use a superpowerful or instant kill attack on a regular timer, but give players Applied Phlebotinum with a certain number of charges that will reduce or prevent the damage. When the charges run out, the next attack will wipe the raid. Most notably used by Kil'jaeden.
 * Atramedes uses a similar mechanic in Blackwing Descent. Both his Searing Flame room-wide attack and his player-tracking beam of fire from the air MUST be interrupted otherwise a raid wipe is guaranteed. Only ringing one of the shields spread around the room will do so but you only get ten of those for the entire fight. When you run out of shields, you're out of time and out of luck.
 * One boss that used to do something even worse was Algalon The Observer, AKA Algalon the Raid Destroyer. Not only did he have the standard Instant Kill after 8 Minuites version of this trope, he also had one far more dreaded by players. If he wasn't defeated within one real-time hour of first being engaged, he would abruptly kill everyone in the raid, and then leave the area. What makes this utterly obscene is that the raid would have to wait an entire week to try to fight him again. Thankfully, however, this restriction has been removed, giving the players as many tries and as much time as they need. However, to completely hammer the point home, he would gravely intone thier failure to do it quick enough, just to rub it in and feed on the raiders' tears.


 * In Final Fantasy XI, certain world-spawned (only one to a world) High Notorious Monsters (HN Ms) will go into an Unstoppable Rage with attack and defense stats sky-high if not killed within a certain amount of time after the fight started. Pretty much certain death. In this case, the dev team put in rage mode as a countermeasure to players attempting to manipulate the spawn timers to keep it in their time zone; players from all time zones (and all around the world) are supposed to have a shot at it.
 * City of Heroes features a number of situations like this in newer missions, where there is a few minutes before the enemy will call for reinforcements. You have to call them off by activating something before the timer expires. Other missions, similarly, will have a response triggered by something you do in the mission, giving you a few minutes to finish up and get out before you get swarmed.

Platform Game

 * In Wario Land 4, after hitting the switch that opens the portal out of the level, you have a time limit within which you have to get to the portal. If time runs out, you start losing coins - when your coins hit zero, you die and lose all the other treasures you got in the level.
 * Wario Land Shake It! continues the trend, except when time starts to get low, you hear the final boss theme, and when it actually runs out, cue Wario in some kind of nightmare place, who gets suddenly picked up by the final boss, shaken until his treasure gets flung everywhere and thrown into the distance.
 * In almost all of his appearances, Super Sonic is stalked by a constantly decreasing ring count. If he runs out, he loses his Super power. If this happens during a battle with the final boss, you can expect instant death.
 * In Sonic CD, waiting for  completely motionless will  . Cue Nonstandard Game Over, regardless of Rings or Lives. Obviously this isn't something you'd do by mistake.
 * Parodied in Cool Spot, a platforming game starring a mascot for the 7-UP soft drink. If you ran out of time, the screen would fade to black and show an alarm clock ringing with the character smashing it with a hammer out of frustration.
 * In Wonder Boy, your Life Meter is constantly decreasing, and must be refilled by collecting fruit. In Wonder Boy in Monster Land, there's a timer represented by an hourglass that takes away a life heart every time it runs down. And healing items are hard to come by.
 * Conker's Bad Fur Day features a multiplayer mode in which one side has to escape past the enemy line to reach a truck that will take them to safety. Taking too long to do this will result in a Kill Sat blasting the escapee(s) to death.

Puzzle Game

 * In Tetris the Grand Master 2 and 3, if the clock reaches 15 minutes, the game will go into instant-drop speed and the delays for piece lock, appearance, and the line clear animation will minimize. However, a round of of TGM2 or 3 usually doesn't last more than 10 minutes, so you'd have to try to get the clock to reach 15 minutes before you die.
 * TGM3's Sakura mode has a time limit for both the whole game and the current stage. Run the stage timer out and you move on to the next (but your stage clear percentage will go down); run the game timer out and it's Game Over. However, if you get stuck on a stage, you can hold down Start to skip it (at the cost of 30 seconds from your total timer). This feature is disabled during the Extra stages, where only the total timer is present and you cannot bypass a stage either by timeout or skipping.
 * As a Puyo Puyo battle drags on, the amount of Ojama Puyo sent with each chain is increased at an approximately exponential rate. If the battle drags on long enough, every Puyo cleared will send a bare minimum of ten Ojama Puyo.
 * In the higher stages of Kirby's Avalanche, a computer will, despite all of your disruption tactics, somehow always manage to pull off an Avalanche (a chain of 9 or greater) if you don't beat them in under two minutes.

Real Time Strategy

 * One of the Pikmin 2 dungeons has the dungeon boss show up if the player takes too long on any given sublevel. Naturally, the boss can only be harmed with a type of Pikmin that isn't made available until the final floor.
 * Lost Magic: If the infinitely respawning enemies or the fact that The Computer Is a Cheating Bastard don't already kill you. the arbitrary time limits surely will.

Rhythm Game

 * The Boss Battle mode of Guitar Hero III would initiate a sudden-death-esque "death drain" on both players if they got far enough without anyone failing. It would deplete your "Rock Meter" steadily, and could only be staved off with points gained from hitting notes. Later games in the series changed this: if both players survived through the whole song, it would repeat, only with the chart on hyperspeed. With each successive repetition, the chart scrolls faster, making it harder to read the notes.
 * Additionally, in Guitar Hero 3's career battles, only you would be death-drained, and it'd be during the opponent's "killing solo". incidentally, it's not getting to the end of the track that results in failure (you don't get close on Devil Went Down To Georgia), it actually IS your rock meter bottoming out that causes you to fail.

Roguelike

 * In the Pokémon: Mystery Dungeon games, when the player spends too much time in a dungeon, eventually some messages about a "mysterious wind" start appearing. If the player takes too much to find the exit, the Pokemon are blown out of the level and it counts as a loss.
 * This is the default mechanic for any game based off the Shiren: Mysterious Wanderer formula. (Chocobo Mystery Dungeon deviates from it as mentioned earlier.)

Role Playing Game

 * In Sunset Kid's dungeon in the final chapter of Live a Live you must find the character's Infinity+1 Sword (a 44 magnum) and get the hell out of there before eight bells strike, each fading out the visibility in the dungeon. If the player can't make it, four dangerous monsters will pop out and attack you. Through some Level Grinding, though, you can get powerful enough to defeat them and get a very useful piece of equipment.
 * Wizardry: Tale of the Forsaken Land. Stay too long on a level, and the Grim Reaper pops out and starts chasing you around. He's as fast as you and can move through solid objects. If he catches you, a random party member gets possessed. If that party member then dies, it is Perma Death. The only way to cure that status is in town. The Reaper also appears in certain areas regardless of time.
 * In the Bonus Dungeon of Mega Man Battle Network 2, attempting to access certain areas will result in a battle with 1-3 Protecto viruses. You must kill all of the viruses in one shot within 10 seconds (as they instantly heal any non-lethal damage done to them and revive themselves if at least one is still standing). If the timer runs out, you're hit with an unblockable explosion For Massive Damage... and the timer starts over.
 * Super Paper Mario will send a flying skull after you if you stay on a level for too long. This enemy isn't much of a hassle (though it takes only one point of damage per hit, it has 4 HP and deals only one point of damage per hit), but it can be quite unsettling when encountered unexpectedly.
 * Major boss battles in Final Fantasy XIII have an invisible time limit that prevents the player from taking too long to defeat the boss. When the timer reaches zero the boss casts Death, instantly killing the party and resulting in a game over.
 * Earlier Final Fantasy titles, namely Final Fantasy IV and VIII, have Odin, who will OHKO the party if he is not defeated in time.
 * And in VI and VII we have the Demon Wall, who one-hit kills the whole party if not defeated in a set amount of turns (IV has it, too, but its mechanic at the end is to crush the party one at a time, so you have a little more time to pull off a win). And then the trope is played with in the Undersea Palace in Final Fantasy V, where the game makes you think you have to defeat Gogo before the timer runs out...but you're supposed to stall the battle (e.g. do nothing) until the very last moment. And the same happens with rescuing Shadow in Final Fantasy VI.
 * In Persona 3 and its PSP remake, Elizabeth, her brother Theodore, and their older sister Margaret have - in addition to quite a few other special rules they won't tell you about - invisible time limits for their Bonus Boss fights, after which they fully heal themselves and proceed to nuke the Player Character into oblivion. For Margaret, the time limit is fifty turns. Elizabeth and Theo are less generous.

Shoot'Em Up

 * Can't beat a boss within the time limit in Zanac? The game will increase the AI's difficulty. Thanks, Compile. In area 11, if the fortress isn't defeated in the time limit, player goes back to the beginning of the stage.
 * Capcom Shoot'Em Up 1943, not to be outdone by Compile, forced players to redo battleship stages if the player could not destroy 70% of the boss battleship. More often than not, the player restarted the level with low fuel and the default weapon. But if the player couldn't complete the mission with special weapons and a full fuel tank, then how...?
 * Some Shoot Em Ups, such as Gradius, Ikaruga and Giga Wing, have timed bosses which, if not destroyed in time, will simply let you advance to the next level, but you miss out on bonuses that would've been earned from killing the boss.
 * Gradius V has one midboss that is guaranteed to take out a life if you don't kill it, because it's taller than the screen's height and, upon timeout, goes from the right-hand side of the screen to off the left-hand side in a straight line.
 * The Spider Tank boss has a Wave Motion Gun that can only be avoided by hiding behind one of the blocks, and it will eventually fire it in a place where there's no cover.
 * Of course, if you're going for a Pacifist Run, the timer running out is your victory condition (see also Touhou Project).
 * Some of the Gradius bosses, such as Big Eye in II, and Bubble Eye in III (arcade) will crush you against the edge of the screen if you take too long.
 * This is especially problematic in Radiant Silvergun, as destroying bosses is the best way to power up your weapons. If you don't level up your weapons consistently, you will probably find yourself in an Unwinnable game in the later stages, and the only way to see the ending will be to have all bosses self-destruct. Even if you manage to survive until then, don't expect a good score without those destruction bonuses.
 * Touhou Project has this also in that timing out bullet patterns (spellcards) prevents you from gaining points from them. However, certain boss patterns can become harder as time passes. The biggest example is how several bosses (generally Extra Stage bosses) have a pattern that becomes more difficult as the boss takes damage. This would normally mean in Pacifist Run the boss would stay in its easiest pattern, meaning it is easier to beat the boss without damaging it. Therefore, these patterns, in the last thirty seconds or so before they are timed out, enter a super-difficult mode that is more difficult than the pattern would ever be normally.
 * In Border Down, the maximum boss time bonus is 3,000,000 points. You get it by beating the boss when the timer is at 0:00. Every positive second from zero lowers the bonus by 60,000 points and every negative second from zero lowers the bonus by 300,000 points. When the boss timer reaches -30 sec, the level ends and you lose 6,000,000 points.
 * Star FOX Command 's battles are timed; the timer is Hand Waved as being your fuel meter; if time runs out, your character just retreats as you lose one ship. The remaining time at the end will carry over to the next battle, even if the next battle is fought by a different character.
 * The boss Macbeth in Star FOX 64 will instantly kill you if you take too long.
 * However, this takes so long that it's probably harder to get that far without dying than it is to just defeat the boss. Other levels will trigger something bad to happen (a building blows up in Fortuna or Katina). This still finishes the level, but you miss out on a secret path.
 * In the little known laserdisc based arcade game Galaxian 3, the Cannon Seed's core must be destroyed within a time limit; one of the characters will announce how much time is left at 20 seconds remaining, then again at 15, and then does a countdown from 10 to 0, at which point you instantly fail the mission, no matter how much shield you have left.
 * Take too long to defeat a boss in the original Darius, and cube-like enemies will spawn at the top and bottom of the screen to make navigating the boss's attacks harder. Some players, however, take advantage of the cubes to get extra points.
 * Time Crisis terminates your current credit if the time runs out; this is a common way to die among beginners due to the strict time limit. Its sequels (except for Project Titan) simply take off a life if you run out of time, but the timer is much more lenient (and restarts on taking a hit) and this never happens unless you do it on purpose or are playing very badly.
 * Certain bosses in the R-Type series crush you against the screen edges if you don't defeat them in time.
 * Defender summons Goddamned Baiters to harass you if you take too long.

Simulation Game

 * Unlike all other games in the Ace Combat series, Ace Combat 3 Electrosphere (at least, the original Japanese version) didn't give you a hard time limit. The time limit in the briefing instead indicated how fast you have to destroy the initial enemies to get a mission update and more enemies (with whom you could totally Take Your Time unless you were going for A-rank completion) and a better mission ending. Said endings mainly differed in dialogue but some resulted in story branching: completing "Ghosts of the Past" on time, for example, lets you play a hidden mission revealing more of the MacGuffin Girl Rena's Backstory, while taking too long gives you the default counter-terrorism assignment next.

Stealth Based Game

 * In Metal Gear Solid 2: Sons of Liberty, if you fail to disarm any of the big bombs in time - the entire structure is blown sky-high.

Third-Person Shooter

 * The "New York Minute" difficulty mode in Max Payne adds a timer that never goes above one minute (except in VERY specific levels) and is refilled by meeting certain objectives in a level. If that minute runs out completely, you simply die.

Turn-Based Strategy

 * In Super Robot Wars Compact 3, the Omega Missile from Mechander Robo frequently shows up after 3 turns from Stage 10 until Stage 16. It has a post movement MAPW with a range of 1-6 around itself that hits for about 4k damage and NEVER misses.

Anime and Manga

 * In the Manga School Mermaid, anyone who hunts the titular creatures has to kill one and devour its flesh before the sun rises. If they fail, they.