I came for the name, I left for the game.
There is no challenge, I think it's boring as hell.
I tested the game on Firefox 30.
-> there is no "Rainbow ball" but sometimes my timer and my points are changing magically. (or I don't understand what you mean with "Rainbow ball")
-> there is no difficulty. you only have to click and see your score evolving.
-> i don't understand why the music is off by default.
-> when i make it on, after one try, it go off again.
-> there is no "mute" button for stopping by myself the music during the game
-> shadows are rotating with balls - for improving that, you should make one sprite with only the shadow, and pinning it on every ball with "Position only" parameter.
IMO, there is a lack of challenge and stress. You can add some achivements :
-> clicking only on ___ coloured ball XXX times without touching any other ball
-> make a "rainbow serie" in clicking every color once
-> click ____ color and ___ color successively XXX times
and if you don't want to use theses rules as achievements, you can use them for making score bonuses ! So best players are ones who are the best in making good series, like in a shmup game ! Because for now, player is randomly clicking everywhere without knowing what he is doing. And it's why I think your game is boring for now.
Continue to update your game, i don't have a fixed opinion