Pretty good work. I like the light and composition of the wall, but the scan is a bit too sharp in some places, mainly around the head, so it doesn't blend in quite as well. Also, the scenery that he's overlooking is way too cluttered. I couldn't tell what it was at first. I like the concept, but there's too much stuff there for it to be a city, and I can see patterns emerging where the same image pops up more than once. Finally, I think there's not enough color. Even the dark, run down city look has different shades of grey and black. What you have looks too much the same.
Other than that, good work!