So the concept for this game is really cool, but I think the execution of creating the game could have been done a lot better. The player controls are way too sensitive, both the maximum movement speed and the mouse sensitivity are way too high. You can actually just fly around the map and avoid everything as a result of this.
It also feels weird that the player can walk up straight walls, and the turrets only aiming along 2 axis (so if you're above them they can't hit you). I also feel like there should have been a way to destroy the turrets. Also the pickups are not obvious and can be quite hard to see.
Lastly it's a bit disappointing to see you have used an asset store model without mentioning it on your entry page or opting out of the graphics voting category. A bit of a strange decision if you ask me as well because the zombie model doesn't match the models and art you actually did create.
So all in all, the concept is a good one but the development could have been greatly improved.