Ok, so thanks for identifying few of my mistakes made in this game.
1: I hope that I will change the typeface soon.
2:You can press Ctrl+S to toggle screenshake and Ctrl+X to enable blur while screenshakes (As I clearly mentioned in this game's website). In future, I wil be changing how will these screenshakes can be triggered and which of them will do.
3: I will try to make the screenshake limited and fix those border impact glitches.
4: I will make sure that I will fix these glitches happening to the ball's reflection.
5: The reason why I added bit gravity to the ball is to prevent balls happening to continuously loop forward and backwards while doing 170° to 180° shots.