Click the billiards cue for it to hit the ball. Everything else is self-explanatory. Enjoy the simulator! (Note: sometimes, if the cue is too far away from the ball, when you click the cue, it might not hit the ball. This is a bug that I know how to fix, but will make the project slower, so just try not to hit too hard.)
Nothing much ._. - no credits; all by me - took me one day only to complete (around 30 minutes)