Nice game!
Firstly, damn you for submitting this in that 8 hour period I was asleep! I didn't even realise it was here until you posted about it in the Mafia :P.
Great game, simple yet fun- that is a good combination.
Graphics- Nice and shiny, not a lot more that could be done with them given the style of the game, and my computer was already laggy enough at around 10,000 points without any more for it to worry about. Maybe could have done a bit more with the menus, but that doesn't really matter as far as the game goes.
Style- Simple style, and easy to pick up and play. The concept is fairly original, and the difficulty curve is just about right, though it does jump quite quickly from being easy to incredibly difficult. I still would have liked to see more colors, and random color changes rather than in sequence, but I know that would have fried my computer, so I'll shut up :)
No violence and Humor, doesn't need them, nor should there be any in a game like this (unless you include me beating my head against my desk when I got trapped in a corner by 5 blue balls)
Interactivity- I don't know what everyone else is moaning about, I like the mouse control, it adds to the difficulty that it moves around a bit. The keyboard control is a lot more difficult as you can't move diagonally, but still playable- in fact I found it easier to avoid balls with the keyboard, but harder to catch ones of the right color. Good to see you implemented the bouncing off the side walls, that really helped.
So overall a very solid 4/5, and congrats on the daily 4th, you deserved it!