The most annoying bug
Okay so this bug has haunted for me for months now, so much so that I feel terrible every time I go to do some work on the game.
Basically, no matter what I do, I cannot get reasonable framerates when there is more than 20 zombies in the world at any one time. It's even an issue on my new computer - a Core i7 4790K - and that's no slouch.
Thus, I'm applealing to the Chaotic Rage community. If you can help me fix this issue, I'll be very grateful.