RPS-reg Roburky has written an interesting if minor experimental game. It's called Reset, and is available at http://www.roburky.co.uk/?p=13. It's inspired by and based around "Rest to Reset" by Trash80 (who you'll know as the creator of the music for Darwinia). Roburky loves it so much he tried to turn its structure into a videogame - the best comparison is an alternate-dimension music video, with a game instead of film being used to illustrate and provide secondary-stimulation to the music. Its five megs, will take less than five minutes to play, and you can get it from http://www.roburky.co.uk/?p=13.