good
but one thing bothers me, the whole having each color represent a different tone is nice and all, except if you're trying to get a high score, you eventually sound like a retarded three armed chimp playing the xylophone while on speed, yea it's amusing, but it doesn't sound good. Maybe you should consider adding a secondary mode where it doesn't matter if you hit them or not, you could just screw around with tones, and then get rid of the tones in the ordinary game.