Very cool.  It's a really simple idea that's been executed really well.  

I especially like the feel of the hits when you mess up.  It has some real weight to it!

A stored highscore and/or leaderboard would be a great addition to keep you playing. 

Great work. 

Surprisingly addictive, you really hit the flow, timing and level of feedback to keep me wanting to hear that chime again (damn I hate how easy I am to manipulate...)

nice, really great concept that incorporates the theme in a really neat way. 

simply, direct and easy to understand. 

i would have to argue, the colors are a bit too intense. but generally i liked the screen shake, and "pause" that you get when you collide. 

good job. 

Amazing game! Cool concept greatly executed! My high score is 57500  xD (high scores table would be a good addition btw)