Great game, loved the music, would make an excellent mobile game.
playing other rythm game simliar to this one, it gave me an idea. Why dont you add up/down arrow and w/s to the controls? you could make like an INFERNO difficulty where you have to use both hands with 8 Buttons to play, or maybe even a multiplayer mode. (If you made it mobile, you could place 4 buttons on one side, 4 on the other)
Great Game, Excellent job :D