There's a lot of awesome detail here, but like DarkcanxD said, the girl kinda looks superimposed onto the background, like a sprite in a visual novel or something. There's also a lot of negative space. The whole scene would be perfect if all the figures and details were more compact.

Overall the piece is nive but I think that the main girl stands out a bit to much, like her color temperature does not mix very well with the background. Again she looks amazing an the background is quite detail so still looks good.