Needs animation and better responsiveness
I don't believe in super-polished games... but this needs a little more. You need to animate the blocks popping and dropping down, at least - otherwise, it won't be clear to someone who's never played this genre what's actually going on.
Also, the game lacks responsiveness at times. Sometimes I click a block and it doesn't pop, and I have to move the mouse around before it will do so. I think maybe you're using onMouseIn or something, so if you pop one block and another drops into its place, and you try to pop that one, it doesn't realize you've got the mouse on it. You need to listen globally for mouse clicks, and then test which bubble you're on.