Passage without pumping. (Dying Light)

There is such an idea: beat the game without leveling. Arose about six months ago when I passed the second time length and breadth of the nightmare.
The third time, want, like, to add realism or something. With a wooden stick the entire game. Well, as it would be in real life.
Can anyone tried it? Maybe the plot is not poluchilsa (without a cat machine, and, in some places, for example)?
Even if it were possible, then cut off to the possibility of sleep. Who is going to do? Just not to sleep that is understandable, but the temptation will always remain.
Or other vary to complicate the life of GG