I like the simplistic style and the changing background color all the way to pitch black. The controls are not quite working yet, though and it might get a bit boring - the game play as well as the design.
The music sounded very familiar to me: I have the same Garage Band loops in a song of the game that I have submitted here ("The Last Secret", my song is called "Secret Stars"). I was very amused that we seem to have the same taste... :D