This game is great for anyone with a large music collection.
Personally I love this game, I am the type of person who loves music but cannot simply just sit there and listen to music, I have to be doing something, thus the concept of music based games are great for me.
Audiosurf takes your song, loads up a track using some formula and your song and then you take a ride on that track while listening to your song. There are mutiple characters to choose from, each one has a special powerup ability. The general goal is to match up like colored blocks and get the highest score possible. Or, with the mono character, avoid the grey blocks and collect the colored blocks and get the highest score possible.
Each track is based on your song, you want a fast track to keep you on your toes, pick a fast song like something by Dragonforce. You want a slow, relaxed song, pick something soft, or if you want something totally off the wall random, there are some Queen songs that are great for that. The game comes with "Audiosurf Radio" which essentially is them putting up tracks for you to play if you're bored of your own music. Sometimes they put great songs on there.
Audiosurf Air is coming out soon, not much information is out at this time, but there is a beta application at http://air.audio-surf.com/