Imo, To much pixel art, not enough buildings. That one ruined house, is not builder grade at all and should be left out, but then again this is all very recruit. I know this isn't your first application and you have used some of these before, you need more new and less old. Also you buildings are very boxy and plain, a building is more than a flat box, its layers and detail, think more about the bones of the building and less of the walls. The best place to start is at the beginning as with the ancients and myself first try to master the arch, a simple shape that is the base for all ancient, Classical, Romanesque, Byzantine, Medieval, Gothic, Renaissance, etc, architecture.The arch is what gave all those styles/eras buildings strength, and stability, it also defined what they looked like.  So my advise to you is this, start at the beginning, with the arch, with the base of what buildings are and to think about the details and whats makes a building look like a building and not just a flat box. Good luck and hope to see you improve.