The farm's main building has it's walls too darkly colored; it would help alot if you used lighter colors. Secondly, the houses who are in the same sheet as the pokemon center have their ceilings shaded oddly, around the tile, instead of being in a descendent order, like most of the houses above.
Also, the background where the tiles are is drying my eyes out.. Use something like white along with light gray or something.
The galactic building doesn't look like it has any depth to it
It would help if you told me how it doesnt have depth, and how to fix it.
I have added a tree to the Customs and have also made the colours of the Houses Better...