So, at random points while playing, the game suddenly starts chugging like I'm trying to play it on windows 98. It almost goes frame-by-frame, can't move, can't open the options menu, because none of the inputs can be picked up because... once again, everything just chugs. So, I have to alt+f4 it, and then if I try to start it up again right away, the intro does the same.

Anyone come across this and know what to do?