Nice music and fun graphic set. You should reinvent the UI design and text graphics again.
I did not get the game completely, i had no idea how to place the purple platforms for the buildings so i could not expand my civilization over the world.
This may have a new levels, building types and different challenges. A very good start: I like how the building are stacking on each other. The buildings should have some effects to to be sure what they do. Upgrading them would be fun too, and breaking the unused parts. Theme would be different; imo most humans are afraid to build houses off the cliffs.
You should change the thumb picture, because it does not show the core of this game to the players.