I had some technical difficulties with this game and Firefox: the music was only playing in the first level i tried, then it stopped and would not play again, but only the music—i could hear some beeps when hitting the notes, but no all, and the “sucking” sound of the black hole. There is also some issues with the keys: when pressing up or down, the event is bubbled to the browser, i assume, and it scrolls the page up and make.
I think this game would be such fun with a smartphone using the gyroscope to rotate the level, if you ever consider it.