*The view from the doorway is poor... only the mountain is visible and it it takes a lot of space and looks poor...
*I also agree with Maston about the light as I suggested earlier.
*Try removing that barely visible obstacle on the right and continue the floor and pillars to the right so it doesn't look so empty.
I'll attach an image explaining what I meant in the LAST TIP.

the coloring/texturing looks pretty good, aside from the above I think your ready for your final .
Benny