Might and Magic/YMMV

Broken Base: The "back to basics" approach of Might and Magic X: Legacy (adapting the old-style system of play with a modern feel) has a few fans - mainly younger ones - up in arms. Many of them would like to see the free movement system of the later games like VI through VIII and the turn-based system done away with.
Demonic Spiders: Shows up in nearly every game. There are enemies that age your characters (nigh-impossible to reverse), enemies that drain your MP to empty in one hit, and enemies that flat kill you (or worse) in one shot.
- Instant death effects should not be a problem once you level your healer, in VII and VIII at least, to cast master Protection from Magic. Just keep an eye on the spell icon in case it ends prematurely. Mana drain effects, however, can very swiftly neutralize your ability to heal your party, turning moderately threatening enemies into this.
Good Bad Bugs: In VII, the range of melee attack for the players is slightly longer than the reach of monsters. The strongest versions of monsters are often the biggest ones - especially the gargantuan Minotaur Lords. The easiest way to deal with Minotaur Lords in Thunderfist Mountain and The Maze is to lure them to chokepoints where they can't reach you and whittle them down in complete safety. This also works on behemoths in The Pit and the tunnels to Eofol.
Narm: The Evil Laugh of Lord Xeen, the Big Bad of Clouds of Xeen in the game's intro is simply hilarious to listen to.
Scrappy Mechanic:
- Might and Magic VIII:
  - Several quests require you to take a specific character into your party to complete them, which is especially annoying considering that the characters are usually underleveled by the time they can join you.
  - The merchants will call you a cheapskate if you have over 10K gold and leave their shops without making any transaction.
  - The boat to Dagger Wound Island offers traveling there on only two days of the week, being completely useless the other five days. This is especially frustrating considering that the boat from Dagger Wound Island to Ravenshore is available all week.