Colonization by units?

[Kamog]

That's a lot of ring worlds! I've never been able to build so many because it just takes so long to do the research and to build all those bases.

To make the game even more challenging, maybe we can make every planet damaging too, so that it's difficult to colonize them. Well, maybe not all the planets. Perhaps the ones close to the star could be damaging (due to heat) and the huge planets too (due to strong gravity?).