There's nothing to much to offer at the moment, but I'm sure there's something you can do with it to make it great. If it's all done by scratch, which it probably is, then you got something great coming out. I see the potential in you indeed...
The tiles are pretty nice, though I probably would like it less when it starts repeating so much. The tiles to the doors make me feel iffy, especially the one that goes through the large door...Probably just me though.
Anything to add...Well, it's rather up to you. Maybe add different floor tiles or some furniture...Look at the RTP items and see what's up and then think what you can add yourself.
Good luck.