Other World Types?

[Draegon]

I was poking through backstories a bit and noticed mentions of other world type like cave worlds. Will any of these other types ever be added? Because colonizing a cave system would rock.

[Canute]

Try to settle at a mountain area, you got enough rock to dig your caves.
Currently the gameplay don't support a map 100% of rocks because invader and trader need free space to arrive.