wow great job.
but...
the floor is too glossy, it stands out TOO much.
IMHO, a reflective floor is not very coherant with such a great moody scene. i would localize the reflections on specific areas to give hint of dirty water, the DOF is great, but sharpen it a bit near the window, the grainy effect does not do it to well,, i think if the area near the window looked (motion) blurred with a slight trail, that would really strenghten your already great composition.
I wish i was at your level, your work is very inspiring.


p.s. my english is not great, oh mon dieu, but try