So what is the game?
Well it takes an idea that Audiosurf has brought to the forefront, that is to take a user's music and create content from that.
This means every single song on your hard drive is a completely new "level" to play, which provides a lot of levels for some people. :o)
Taking from another genre: The sideways scrolling shooter, the idea is to have the music time bullet shots and enemy spawns. The user just moves the ship around and tries to rack up as high a score as possible.
Exactly how well this will work I'm currently unsure, will see.
Right now I've the skeleton of a sideways scroller with all the music analysis code still to do (big job).