Cheap, Original, and Creative!
Audiosurf allows you to take your own music library, and race through a multicolor and multi-effect track to the rhythm, beat, and speed of the music, and now it allows for custom modes and stuff, which really add to the feel and enjoyment of the game. It is a game which will never get old because you are not forced to use a game soundtrack which may contain songs that you find annoying. You get to use your own music, so it is great even if you do not have much time. Just play a song, or play your entire library. All your choice!
The graphics and the effects in this game are just phenomenal, and surprisingly, the game does not require extreme hardware or anything to run. Also it allows you to update your Last.fm profile if you have one with the songs that you play as you play them! Plus it is available on STEAM for only $9.99. It is still one of the best buys that I have made to date! Love this game, if only it got the attention it deserves.