I'm working on making a base card game, like the game tabletop simulator but made so my friends cant peek at my cards

I started off with something a little different but some of the code from this will help me to making a real card game simulator.

CONTROLS:
Left click - place 1 card
Right click - spam cards
Scroll wheel - change gravity
C - clear screen (remove cards)
Arrow keys - apply force to all cards
Space bar - make all cards "jump"
#1-5 - change the framerate limit (vsync = 0,1,2,3,4)
Escape - exit
If you have any suggestions as to how i can improve my code, please go ahead and tell me, thanks