I ran out of time to do a million things and adding player/enemy hit collision and making a proper game loop was one of the  things that didn't get done. On the plus side, the game won't end preventing the player from running through all the levels, so ¯\_(ツ)_/¯

I noticed the same thing on my Macbook Air. 

I can only imagine all the things I goofed up.  I *think* I set limits for all the groups, but I wonder if my player bullets are leaving abandoned husks around... lol oh well