Hey, looking pretty good! Some UI elements might be confusing at first glance. I assume the 100% is health, but it's not immediately clear which of the other numbers is armor or ammo or what. Also, it's not clear way the little - and + indicate. I do especially like the key in the inventory above, though. The weapon selection indicator is also very good. The lighting is pretty nice, too. Keep it up!
I think I'm going to have to go and check how other old FPSs did their HUD to designate what each element was. I wouldn't say it's purposely confusing, but it's purpoisely a little bit odd to simulate that good old Eastern European jank, but I could probably make it clearer without sacrificing that feel. The - and + are supposed to be ammo and health respectively, but I guess they don't really come through. It might just be a matter of having clearer symbols maybe?