Great game overall.
Quick suggestion: make mouse controls to be as responsive as keyoard. As of now player orb moves too slow under mouse controls to be even compared to the speed of keyboard.
On level 4-7 game pfysics somehow takes "preferability" on one side like there is a some kind of mass center - projectiles flying towards right side of screen fly faster than the ones launched to the other side. Which makes left bottom button significantly harder to push.
Need a bit more time (1-1.5 sec) before collapse - some times there is an unlucky occurence when gap is simply too far away and you cant reach it nomatterwhat - its an autoloose, and IMHO autoloose is a bad thing.