Fantastic game but it would be really nice if there was a reward that repels 1 or 2 biters because getting REALLY far and then getting killed by a biter you didn't see is frustrating to say the least.
tactic to beat the final boss:
use the gun spawn perk, and then go in shooting. as soon as you hit the level, drop down with the down arrow key. keep jumping around grabbing the box that's always on top of the level because of the perk and you should beat him after a bunch of tries (took me about 15)
And by the way, it is a load of crap. On the earlier levels it's fine but around level 7 it becomes an unfair game. It's not fair challenge. It's enemies that just rip you apart. 2/5.