Since the creature stage, I experienced problems with the unlimited complexity cheat. First, my creatures turned invisible. I soon discovered that adding too many parts lead to that problem. I was able remove some parts and make the game behave normally but the creatures textures soon started to flicker. I was able to make it through the stage but when I enter the tribal stage, I can only play for about 45s before the game close with a Windows ''Program crashed'' window. Great.
I got a fairly good computer, and my G15 does not indicate any stress on the computer (about 60% CPU, 40% RAM) so that's not the problem.