I think the physics of this game are super cool! I love the lighting effects and the way you can sometimes bounce up and down with the ball. I definitely can see potential with this game; however, I ask that you relook at the sensitivity slider, as even putting the sensitivity all the way down was too much for me, and I had to stop at like the 25th upgrade. It would also be nice to have a hotkey to bring up the shop rather than going back each time. Knowing when you had money was also a bit unclear, so having some sort of money icon on the screen would be nice, as well as maybe some background music. Besides these little flaws, though, I do enjoy the concept of the game, and I think it will be even more fun after adding more balls! Keep up the great work!