In survival games the threat of death is omnipresent. Even when the environment and its inhabitants aren't trying to kill you, your own in-game body is a liability.
Graham offered up a definition of survival games as those where you risk death through inaction. In just standing still you're courting the grim reaper because your body temperature, your hunger, your thirst will continue to change. It's a more realistic depiction of the body than you often get in gaming and yet it comes nowhere close to approximating the threat your real meaty avatar can pose.
