SPOILERS FOR THE LAST TILES. And how to get Atlantis and a way to get Powerhouse. I have everything (17/18 tiles) except the top one in the disconnected leftmost column that shows up near the end. Help for that, please! Also, help for how to get Atomic, Scorched Earth, and Factory.
Disconnected, leftmost column tiles, from bottom to top:
1. Steam = Fire + Water
2. Causeway = Lava + Water
3. Ash = Forest + Fire + Fire
4. ??
Tiles past the fifth column:
Wheat = Ash + Ash + Plains
Village = Water + Wheat + Plains
Some achievements:
Atlantis: Village surrounded by 6 water
Powerhouse: Wheat surrounded by 4+ villages works