Excellent Julius!
I'm happy I waited to play the rest of this after you shared your progress with me. This did not disappoint. The core concept is super frustrating: "make pixel perfect physics shots with different shaped billiard balls." However, two things you did turn this from daunting into a challenge: 1) quick restart. Being able to rapidly try different approaches with a flick of the mouse and a key stroke make each attempt fast without being meaningless. and 2) the 'last shot' shadow. When you think you're close, there's a very clear indicator to help you home in on the solution. These two things take the game from 'average physics puzzle' to 'super enjoyable and makes the player feel clever'.
Very well done. Congrats on a great entry!