A really fun and novel take on rogue-likes. It's like someone took a dungeon crawler, crossed it with DDR and slapped on an awesome chip tune soundtrack by Danny Baranowsky. Highly recommended (and on discount for the next day or so)
G+: A really fun and novel take on rogue-likes
Also runs on Linux (though crashes because my Microsoft Arc Keyboard presents itself as a Joystick...)
Reminds me of Audiosurf.
Same genre of "beat matching" game. It even has a mode where you can use your own music, but I've not had too much luck with it (always instant-ends the level)