Oddly enough for some reason my unity player works very well. Don't understand your complaints, and the games you say have good unity are horrid for me.
Hey,
1. Invisible zombies once you add fog in survival
2. Unlimited Ammo box is cutom is unable to be selected
3. "Safe place" stuff is bullcrap. At least add invisible walls on the edges and tops of the map, but not the higher areas like rooftops.
Fix it.