Zombies are Awesome. But who wants to be stuck in a building? Unlocking one room at a time? The ArmA 2 engine provides 1000km2 terrains in which to explore. My missions utilize this to create an epic zombie experience. Enjoy!
This is extremely good but the zombies are dumb as bricks and zig-zag like total trolls on their way to you. They also stand still and wait 6 seconds before slashing you from seemingly 10 feet away. No biting, grabbing, or tackling--very primitive AI, even Ps1 era Resident Evil AI is smarter.
That said, at night time, with friends, during overcast, and fast time off, it is effectively immersive. Arma 2 lends itself well to horror mods, this much has been known for awhile. My friends and I had a scenario that was basically blair witch project. We ran into a cabin and went inside and found a priest in there, my friend was using a priest skin so I thought it was him and sat next to him, then my friend says, "C-zom, where are you?" and I look up at the zombie and it begins to eat me. Scary, unscripted, dynamic stuff.