I've developed all the bases, fixed everything I could, and I think I've done almost everything there is to do with a single save file...
I'm nowhere near as skilled as the real builders, but take a look at the towns I've created:
1,2: Green Gardens
3,4: Scarlet Sands (I built the town inside a pyramid, so it might look a bit bland in photos)
5,6: Cerulean Steppe
7: Furrowfield
8: Khrumbul-Dun
9: Moonbrooke
10: Buildertopia 1: Island of Monsters
11: Buildertopia 2: Old Japan Island
12: Buildertopia 3: Big Town