The World's Hardest Game 2
The World's Hardest Game 3
Getting Over It
Vex 7
Vex 8
The Impossible Quiz
The Impossible Quiz 2
Deepest Sword
Tomb Escaper
Bad Time Simulator
Just One Boss
Cuphead: Aviary Action
Level Devil is the platformer that lies: every level hides a trap that breaks the rules, and the joke is that you fall for it anyway.
Level Devil looks like a simple platformer and behaves like a practical joke. Floors vanish, spikes appear where you were about to land, doors move, and the level itself changes its mind halfway through. The point is to die, laugh, and learn what the level is really doing.
It is not a rhythm game, but it has the same loop as the Sans fight: die, learn, retry, and a level that seemed impossible becomes a sequence.
It is unfair on purpose and easy once you know the trick.
Dozens, with more in the full game.
Level progress is kept in the browser.