Your drawing was promising, now colors and shadows are delivering that promise.

Given the recent ramblings on shadows... (and I tell you this with urgency before you do any more work) - rooftops are hit by direct sunlight if the sun is at 69ş, unless the roof is inclined at 70ş or more (which is swiss alps kind of roofing). Which is a good thing, you don't need to shadow rooftops, only highlight a bit those that face the sun more directly.