Well, things are happening quite fast in this movie, mainly in the second half so I'm still trying to put together what really happened.
The story starts with four friends going to camp in a wood, one of them decides to make a documentary of the event (or about his friend camping as stated in the beginning). The tool of making the documentary is a hand-cam, so the atmosphere is quite the same we already know from several other films (not bad, actually, the only thing that disturbed me was the blinking light during the last about 20 minutes). The beginning is quite promising, our heroes arrive to the forest, tents up, campfire burning. (However, I don't really understand why they came by a kind-of trailer when they planned to sleep in tents... Well, I admit that it was useful for some subsequent scenes.) Night falls, strange sounds from the woods, next day a strange hairy creature in the woods, next night sounds getting worse, everyone is getting scared, they decides going home but one of them disappears.
This is the point when things are going wild and you better not even blink if you want to follow what's happening. And the point when the expected value of your IMDb vote starts to drop. Rapidly. Because from now on my perception of this movie was about like this: run- continuously bumping camera and blinking lights -dead body with neatly arranged intestines-run-some screaming (thanks God not too much)-a tractor-a strange place-please stay calm you are in a restricted area-run-hairy creature attack-run-some houses-another hairy creature attack-scream run-a huge complex-crazy zombie attack-reinforcement arrives-even more crazy zombie with hairy creatures-run-run-run-friend's head blown off-military helicopter-end.
So my biggest problem is: WHAT? I assume it was about some research lab (at a point we can see a revolving DNA on the screen-saver of a computer) doing bad-bad things to people and maybe animals and of course things go out of control and our friends here entered a place for camping they shouldn't have (this is all just a wild guess anyway). But how? And what? Too much things are happening in a very short period of time. I don't mind thinking during a film but I'm not really into putting together the pieces of some crazy puzzle when the whole picture will also be a complete mess.