I want to like it.
I want to like this flash, very badly. It's got a good premise behind it, it has the potential to be a lot of fun, and it could even easily expand into online multiplayer scenarios if you wanted to work that hard.
But the controls are akward. The timing is on the "too short" side of acceptable. The game could be a lot of fun, but the timing is the one thing that's going to hold you back. If the animation only registers me hitting every third note, there's something going on that's a bit funny.
Great attempt though. It's still fun to play even if the timing is off. I definately enjoy it, and please, if you get the timing right do release another version. It'll be awesome!