The overall picture looks very nice, the only thing I would change is the girl. She's holding a gun, but her expression doesn't say badass or threatening to me, so much that I noticed the gun in her hands after looking at the picture for the 2nd of third time. I took the pose and it was very hard to maintain, let alone trying to walk like that. Lastly, I feel the composition would be a bit stronger if she wasn't at bit a the back like she is.
That being said, your work on the background is lovely and wish you the very best of luck!