I like this game, especially the FPS-defense aspect. However, I think there are points open for improvement.
Here are some suggestions:
Looting/survivor system - instead of dying/missing, give them an injured status which you can heal them by using the time currency.
Inactive survivors - Add a fifth role-slot for survivors, make it boost the group's morale.
Guns/Ammo/Upgrades - When I find a weapon, I will usually not use it since you don't need something else. Give the player the ability to upgrade their weapons, or even add an ammo system.
Fence - it gets very irritating when a bullet-spongey zombie (old lady with blue hat) soak up damage and get away with it, make the player able to shoot them behind the fence. Replace the wall with a chain-link fence or something similar.
Dead Zed bodies - the bodies should disappear, the yard was pretty much covered with blood and dead bodies.
Overall the game is pretty good.
Last thing, I don't think the tag "upgrades" belongs here...
I just hate it when the armored zombies wont fling off even if their arms are shot off (basicly makes them invincable). Need to redo sooo much...Still a great game though!
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