i really like the mechanic of using bumpers to change the colour of the ball. i wasn't able to get very far because i'm not very good at this kind of aiming game. i'm wondering if you could create an 'easy mode' where the shots require slightly less precision or the guide line is longer. this might help less skilled players like me enjoy a few more levels.
over all, very nice work. the physics seem quite realistic and the graphics are nice. well done!