There is something a bit wrong with despawning - projectiles and players aren't being cleaned up properly. I made a really simple gui using pygame which draws all players and projectiles with online=True, and you can see lots of stationary objects.
I tried changing the code to just remove them which helps a bit but it's still a problem. Is there some reason for keeping projectile and players around with online=False, why not just delete them?
See PR #7