-The brick texture is no good. It looks way to clean and repetitive.
-Also the lighting is to even and does not suit any atmosphere. Think of a more scenic approach, ask yourself where to draw the players attention to, put some visible light sources to make it a believable scenario. If you have windows, then there will be (daylight colored) light close to it-contrast that with dim bulbs (yellowish colour) dangling from the ceiling or harsh industrial tripod lights, maybe hinting the way the player has to make through your room. Make your ambience the same color as the leading light colour in your room to soften the border between lit and dark areas.
Use the crates not only to fill space but to fence your player OR to force his ways OR to give him shelter from bullets...depends on your desired gameplay.
Keep on working on it!
I am Jacks complete lack of surprise.