Good concept, but didn't really enjoy it.
Interesting game we have here...
It has a truly unique concept for a puzzle-type game, and I suppose the physics of the balls are developed well. It even has unique balls, which when clicked on, do special effects. The music was also well chosen. But that's all that's going for it.
It was a bit of an annoyance when at times, a ball was unable to touch two other ones because it got stuck in place by a ball above it. I suppose that was part of your game design, though.
Easy mode and Normal mode were perhaps the only two worth playing out of the four. Infinity mode played like some kind of practice mode. And I don't know what to make of Rapid Mode. Is it supposed to last for one round until the time bar depletes and are the balls supposed to fall down that slowly? It may be a glitched mode; I'm not for certain.
To me, it's a good distraction for a few minutes, but the initial mix of balls and the possible outcomes of the balls that fall after getting thrust in the air are way too random. Either that, or I have no taste for this type of game (and therefore my review can't be trusted well).