Give Up, Robot is a psychedelic platformer about a dancing robot. A sinister voice tells him to give up his quest at every available moment (à la Portal), but still he battles on through 60 levels which become more intriguing and clever as progression is made.

The game implements a grappling hook system, so prepare to do a fair bit of swinging between moving platforms and dodging spinny things of death. There's some wonderful level design around level 25 onwards that really got me smiling.

Great stuff. Play it over at AdultSwim.