The level design looked really nice, I'm all for the PS1 graphics (´∀｀)♡

A crosshair for the shooting would help a lot because I wasn't too sure where I was aiming lol, and to be able to refill bullets or slightly less zombies |⁰⊖⁰) lmao

Looks good tho, sounds good, be cool as a little shooter game for sure (｀∀´)Ψ

Hey nice job! I can tell you put a bunch of effort into it all though I do think it can improve.

Accouple of recommendations that might help you out: 

1. Presentation: I think one of the most important things to keep in mind is that your color pallet and design are eye catching. When I saw your emblem for the game and then ran your game I noticed the emblem doesn't reflect the art style or look of the game. If you can try to keep those one in the same :)
2.  The first 30 seconds of any game are the MOST valuable. Try to utilize that to your advantage.

Keep working on it and polish it up!