I like how this turned out. The texturing on the walls/stairs/etc gives a lovely metallic effect and certainly shows a large degree of weathering. Given how the rest of the piece lacks outlines, the line at the edge of the stairs where it meets the wall stand out a bit (after looking at the picture for a while) and perhaps could have been blended in better with the same lighting and shadow twists you've applied to the rest of the picture. Additionally, the light coming in from the hole above is a very nice touch, and quite well done. The only thing that sticks out about it for me is the direction of the sun rays shown (coming down and in) but the wall behind them being fully bathed in light as much as the floor. That would suggest light coming in straight from above (which the vertical shadows under the ladder rungs suggests). Despite those minor critiques, the long hours and computer derps were all worth it. Nice work.