Not bad, being a stock-photo kind of wallpaper. There are a couple of mistakes and not so correct elements here and there though: one that has been pointed out (the extraction, the character feels paper-cut in some areas), the others would be:

- The brick wall is not exactly correct perspective-wise. Why? Because it has no depth at all. That would be correct if the horizon line was actually placed exactly where the brick wall ends, but the horizon line in this case is way above the wall, as the background/skyscrapers skyline indicates. For that reason, the viewer should also be able to view the top part of the brick wall even if it's by a very slight amount.

- The fires in the background are too saturated. Remember that a rule of thumb in illustrations is that objects placed in the very far tend to blend color-wise and lighting-wise with the the background colors. Your background colors in that are are dark blue and very desaturated, for that reason the fire and the smoke should reflect that to show depth and be as much as desaturated or somehow reflect the blue hue of the background.

And that's it. It's a nice idea, and you could eventually rework this and paint over it, turning it into a nice digital matte painting. :)