Wow, that definitely got easier as you kept playing. You should put 6 and 7 at the beginning, and then do the rest. A "you win" animation or display might be nice, it kinda leaves you hanging. Nice game though, great physics!
I think the learning curve is really high, almost prohibitively so. The first few levels should be easy, facing forwards, and then you can start making it backwards as a challenge. Better instructions, and maybe some practice levels, would also be nice. Actually, practice levels that you need to unlock to beat the real levels (the ones you have here) might work best.
Biggest and easiest change you can make is graphics. You're abusing gradients, and you can take out a few colors to make it a bit less shocking to the eye.
Pretty boring. It would be a lot more fun if you didn't have to click, and would involve a lot more skill. Also, the entire thing with the speed of the bounce is a bit strange. I'd suggest taking it out entirely.
First of all, I like the concept. The execution of it is a bit lacking, though... there's almost no user feedback, which is essential. It has almost no replay value, because you're just launching something, there's no obstacles of any kind. The graphics could use a lot of improvement too.
There's a problem when you're losing lives, I once lost four lives when a bunch of enemies came at me from all different directions. If you're checking all the enemies once per frame, and subtracting lives accordingly, that would cause the glitch.
Wow, I really like this game. Looks like the kind of game I'd like to design! Simple graphics, good music... awesome!
It has a few small problems that can be fixed pretty easily. First of all, the reactions between balls, like when you run into them, aren't quite right. The ball being hit gets pushed too far back, and it isn't very smooth. When you're picking up anything, too, you're using the bounding boxes. Because you're using circles, it would be easy to make it so that it's a bit more accurate, by checking the powerup's distance from the center point of the circle. Also, it desperately needs a pause button.
 "Whaa"){kind=icon}
 "IK demo")
 "Kermix"){kind=icon}
 "Turtles of Terror")
 "Sola Rola - The Gravity Maze")
 "Dravalanch")
 "Snorol")
 "keep it up v1")
 "Breakball")
 "More Mindless Violence")
 "Cannon 3000")
 "Many Worm v1.1 Flash!")
 "Vect")
 "Multiball Madness")
 "Crazy Mammoths"){kind=icon}
 "Rebound")