Dear Captain,
Nice work. I look forward to you reporting a medal or two. The only ideas i might suggest is the uniformity of the wall colors. Walls are dirtier closer to the ground. You can use washes, or pastels to blend in more "grunge" lower down. I have even spritzed some matte medium, mixed with water and white glue and a drop or two of dish soap as a surfactant (to break down the bubbles) on a wall and "fly-specked" some extremely fine dirt on the wall.
"Fly-specking" is taking the medium you are using like dirt or pastel dust, etc. on a creased piece of paper that is horizontal to the wall and blowing down on a 45 degree angle to randomly scatter the medium. It will stick to the wetted wall just like the real thing.
Sealhead