So here is my pointers on a quick play though.
Here is a spot where the squad kept falling off part of the building and needing a hand up. This ladder also could use some sort of light around it so that the player can see where he needs to go, cause if there wasn't a huge pile of zombies stuck at the top it would have taken me a while to figure it out.

Also this spot could use some sort of physics push with a toggled player clip because I got stuck in this pile of rubble when it collapsed...

When I was holding off a bunch of zombies waiting for the helicopter this happened, and ended my game rather abruptly...

Other then those specifics and the ending crash I thought it was pretty good. Only one other thing I would change and that was the screen shakes applied in the apartments with the caving floors. While it wasn't to bad at first, it made it quite difficult to find the exits and made things a bit frustrating. Maybe some randomized screen shakes or maybe a bit less on the shake intensity would do imo. Oh and one other lighting tip, I would place some ambient lights behind far view buildings that would have logically provided sources like spot lights and fire. That would draw out detail of your other buildings better, so then there would not be this massive silhouette of a building outline in the distance. Just a mapping tip, other then that I think the skybox light was actually alright when I got in-game.
Was fun though, hoping to play it again without the crash. Hope these pointers help, from one modder to another.
