I like the play between light and dark. There are enough details to make this interesting, and the flatness makes it look like a cartoon world. Good job. Too much blankness on the left, but that's minor.
This shot fits the challenge very well, really conveys that sense urban to me very well. The only thing that would have made this shot better for me would be the lighting, the left side is too dark for my taste but otherwise, good job!
I wish I could see more of the brick detail on the left. I like the play of light on the building on the right; maybe that could have been more prominent in the photo.