I enjoyed the game. The art was good and coherent (I loved the sprayer weapon, the particle effects and reload animation were great), The sound and music were good as well.
The gameplay was fun, The variation in the weapons was superb. I loved the building mechanic but sadly it wasn't really that useful. The controls were a little weird, I feel that maybe it would be better if W moved the character forwards based where he was looking and not just a preset direction (same with the other buttons as well of course). Also, a way to rotate the camera is quite needed.
There weren't really any bugs except maybe that some zombies spawn in unreachable areas. Also, the AI is ok but still needs a bit of work.
I feel like the game could've been even better if it was like a tower defense game formula:
Phase 1: You have a few minutes at first to set up defenses.
Phase 2: A wave of zombies comes in, destroys the defenses, tries to attack spots with civilians.
Phase 3: The round ends when you kill all the zombies, repeat from "Phase 1" again with tougher waves.
Overall though, a great game in the short time limit that we had. Good luck in the game jam!