This game Doesn't deserve the fake good reviews, so please stop with the crap, I actually bought this garbage on sale.
First of all, the introduction and the first impression from the game is total crap, it's right tho.
The graphics.... are crap, the "designer" made some random crappy textures which repeat themselves, there's a horrible path finding, you can actually get stuck in a level, because you have NO GOD DAMN IDEA WHERE THE HELL YOU NEED TO GO.
The game tries to be like Left 4 Dead, (and eve the .exe file is called L4D.exe, that shows all the awesome work that the developers made with that bad and ugly source game) but fails in every try, the story is bad, there's a coop system, which sends invite to all your friends when you play, that could be good, but then it takes an hour to explain to all your friends what the hell is "*insert random symbols* CLICK HERE TO JOIN" means as a game.(In Steam)
There are a lot of bugs, animation issues etc.
The multiplayer is also crappy and buggy as hell.
Bottom line: Never buy this piece of crap, only if you want to laugh with some friends at a lame production game.
Cheers!