Thanks for all feedback. I see that the game is found too hard. I will make easier levels. For a short demonstration of possible tactics watch http://www.youtube.com/watch?v=iUZPvWyzByI
It was not intended as a tutorial but will do until I make a better one.
The game has extraordinary and busy graphics, it was intended more as an artwork than game. If it distracts I will simplfy it. The patterns are oriental patterns, which were found to have extraordinary mathematical properties in the past few decades, therefore cought my attention. Sorry for there is no sound, will be added. Marbles get damage proportional to the velocity of collision. Infact once you set a arrangement of obstacles that works you will see that they die pretty easily.
Please state anything that you see can be improved.
 "Gravity Physics Defence"){kind=icon}