I like this as well. Nice work.
If you don't mind, I would be interested in where you put the flash. I think I can tell but the shadows obviously have multiple sources.
On the upper left the border between the sky and the dark upper wall has a narrow bright rim. Is this a down-sampling issue, a sharpening issue, a jpeg issue or something else? I ask because I seem to be fighting these rims all the time in borders between dark and light areas and it seems they arise from multiple causes.