orcishgamer: I have to give serious props to this game. This was one of the best games of 2011, imo. There's an Easy mode for the musically challenged, like me. It works fine with keyboard or gamepad.
worlddan: Aren't this game and bit.trip.runner and audiosurf all essentially the same type of game. What's the difference; which one is best.?
Audiosurf is more akin to
Klax than other games, with differring modes nad whatnot. Also, creates levels from your music.
Bit.trip games are not generated from your music, and range from Pong-likes to shmups, where you get more layers in the soundtrack the better you do. I think they have like 3 songs each.
Sequence is pretty much Puzzle Quest if you exchanged the match 3 puzzle for DDR/Stepmania. All of them are very different, but are music-based games.
Personally, my current favorite music-based game is Beat Hazard.
Edit: The gameplay is fun, but the writing may be offputting to some. For example, there is an item drop called "Polish Remover", when you check the description, it reads "Hitler". So, if you are offended by such things and internet memes and the characters trying to be edgyyyyy, avoid. The gameplay is fun though.