Really good starting point! I love a good FPS game and your aesthetic to match is really good, I love the art style and sound design!

Big big first thing which malek brought up as well, I'd recommend doing this before anything else, is to add in a mouse sensitivity slider. I'm guessing this is made in Unity, and Unity tends to crank up default mouse sensitivity to 11 for some reason - especially for an FPS, mouse sensitivity adjustment is super important.

Next thing I noticed was some potential small tweaks you could add in for clarity of user experience. It was a little hard to tell when an enemy was hitting me if I wasn't looking at them, and I had a couple times where an enemy spawned behind me and I didn't realize until I was dead. Granted, I think the player should have to be constantly looking around and aware of their surroundings, but I also think there could be a stronger audio cue for when the enemy is near you, when they're attacking you, and when you've been hit (being hit should have a visual cue as well, such as the standard red-flash around the edges of the screen that a lot of FPSes do).

Other than those couple things, this is a really strong start! Just needs a little polish on the mechanics and the UI. Would love to see what direction you take this whether that be a roguelike or something else.

Sound effects and AI seemed solid.  The only thing I'd say with the enemies is what Malek already said: that the enemies coming at the player constantly seems like a better fit.  I think it depends on what you're going for with this one, though.  The "Last Stand" feel seems  to be aimed more at a wave survival kind of situation?  I think for a game like that you need the enemies to be constantly going after the player.  In a game that's focused more on exploration and survival it fits better to have enemies "patrolling" or even just chilling in a certain area that won't get aggressive until you get close, but I'm not sure if that's the case here.

As a player, I think it depends on where the game is going.  I could see this as a rogue-like where you have to explore some western areas fighting skeletons, or as a wave survival game.  Either way, I think more guns, some kind of power ups, some enemy variety, etc... is what you'd need if this game was going to be published.

really nice! the enemy ai was nice but it was a bit simple, what i ended up doing most of the time was just stand against a wall and shoot at enemies since they dont run at you unless your close or shot them which made them not to hard to deal with. the sound effects were nice and fit well. one thing id recommend adding is a mouse sensitivity setting since my mouse made the camera fling really fast and i had to move my mouse very slowly to do things