I really love the style you depicted your map, and I like the slight elevations and colors you chose. Arsheesh is right about the shadows... other than that, the only thing that stands out to me are the fences. In the bottom left clump of houses, for example, two houses are sharing the same back yard. And, in the same clump, there is a house that hits the fence at a strange angle... it makes a little slice of yard that is cut off from the rest of the yard. But overall, I really like it.