Horror style

Now that's was frightening and exciting.
Maybe even too horrorish for me. :D
Campaign is reasonably long and challenging and looks visually awesome, though concept is a little bit.. strange.
From Slender-like forest into Half-Life styled labs, then Silent Hill torture pits and finally graveyard's fresh air.
Good optimization, no errors, no crashes, everything's smooth.
AI navigation is nice, didn't have any problems with bots, they picked up everything we've come across.
A lot of well-placed supplies, a lot of places to explore.. a lot of zombies to kill. 
Lack of hints is easily compensated by bots guiding and telling something like 'Down there' or 'Up the ladder', so that's not a problem.

Great campaign, would love to play again someday.

Interesting map.

Long, confusing and challenging campaign. Too dark in some places, you've literally got to watch your step.
Easy to get lost in maze-like maps. No hints besides some arrows on the walls, rare throwables, very frequent hordes appearing all of sudden, not much visual details, minor bugs like supplies outside the saferoom somewhere in the air, though it's all doesn't ruin it.
And... 5 tanks in the end? Well played. Ended up circling around the maze alone with three of them and witch, bots took down other two tanks and died with honor.
Still, I guess it's a nice map to play with friends.