Such a weird game! More of an interactive world. But it has a goal, and is a lot of fun. Suffers from a lack of explanation, you might need to read a guide. But the ending is surprisingly poignant for such a minimal experience.

Cute point and click game, like a second-string Monkey Island with dogs. Generally funny, with some surprisingly mature humor. Also contains a very humane hint system that means you won't get frustrated.

Not a pinnacle of the genre or anything, but enjoyable.

In short, Audiosurf + Geometry Wars. Not as well-concepted as either, but it's still fun to blast away legions of enemies to your music. As you play, you rank up and unlock ship improvements, which adds a bit of incentive to play. Unfortunately, this also makes it feel a little pointless when you reach the max rank and get the fully-powered weapon at the start.

I wouldn't pay full price, but if you like musically-generated games, jump on at $10 or less.