Aside from some narrow halls and a couple of dead ends you have a nice layout happening. The few halls that are too narrow (and also short height) can easily be fixed. Same goes for hallways that come to an end. Even a short hallway will feel tiring to backtrack a few times during a round. If the pickups are placed right, it's ok to have a few dead end hallways. Like the armor in the water. That works there.
The atmosphere(texture and lighting) wasn't too good. I found it a bit bland, tbh. But stuff like that comes with experience. It can be hard to match textures. And everyone has different tastes. As for geometry, just think bigger and wider. There should be plenty of room to side step and jump around. I have given you a 2/5. If you fix those tight hallways and dead ends and maybe rethink some textures I will definitely bump it up.
Post this over at www.akimbo.in You'll get more comments. AC stuff just gets lost among everything else very easily here.
