Its a great back story, and a really good start on the map, but there seem to be a more than a few shading issues on the rooftops. At first I thought that there were only 2 light directions, but then when I started marking the ones that didn't fit with the majority by being shaded apparently on the opposite side, I realised there were more than just 2 directions involved.
Is this CC3, or another app you are using? The reason I ask is because I might be able to help if its CC3, but I've no idea how to put it right if you are using similar software, like Dundjinni or Fractal Mapper...