The zombies feels too fast for me. If they have to be that fast at least let me see where they are before they see me. Hotline miami does that, it lets you plan ahead (remember) and then execute. Here I think the main problem might be the rather limited vision.
I wish that I could restart directly in the level instead of clicking on the button, I died A LOT.
The reload felt a bit too long and it would be even better if it was automatic.
You created something really cool that gave me Alien swarm vibes.
You should consider adding your names to your itch page, just to make anyone know that you made this :)
Congrats you made something fun.