Quietus is a little flash platformer that really evokes the Castle levels from old Super Mario games. or any of a number of games I used to play on the MSX, like J.P. Winkle or Castle Excellent. It starts easy enough, but get really difficult really fast.
I Jumped out of my seat when I saw the first giant worm.
There is supposed to be a story about being a hanged man trying to escape from hell or something like that, but to be honest you can skip it and just play the game.