Visually i think you did a really good job at giving off a creepy ps1 style. I think adding a bit of fog would add to the feeling even more with these textures.
The zombies dont seem to move faster as the rounds progress so i started to run around trying to find them so i can get to the next round.
The sensitivity is an issue i see other people saying and I agree. It would be cool to see what other types of weapons you can add to this. It felt really good to upgrade to that automatic gun upstairs.