8. The Trick Boss
One of my pet hates in a game that usually occurs near the end, you'll face off against an enemy and defeat it with a surprising level of ease. Why is that? Because, of course, it's
not the final boss, but a mere trick to try and catch you off-guard; a far stronger enemy will then emerge, perhaps a new form of the boss you just vanquished, and that's the one you'll struggle through. Level 5's stunning RPG Ni No Kuni made an art out of this; the end of the game has three bosses in succession who must be defeated without a single save, which proved infuriating the first few times I tried to beat it. The Final Fantasy games are also pretty notorious for this, though thankfully it doesn't abound anywhere near as frequently outside of the RPG genre.