Hmm.. while you're looking at planet takeover, can you please put in some code that destroys all (or all but 1) existing pop when a planet is conquered by an incompatible civ?
I would define "compatible" as Carbon/Aquatic with Carbon/Aquatic. Synthetic only with Synthetic, and Silica only with Silica.
It is slightly rediculous, immersion breaking, and game-breaking that a race that spends so much time and resource to build more pop gets unlimited instant free pop conversion if they take over a meat planet. It is only slightly less rediculous (but more amusing) that when a meat race takes over a synthetic planet, the robots all start having babies.
One other thing I think is very silly is that conquering a planet that has an Capital City keeps the Capital City. This is also nonsensical - if I can have multiple Capitals, why not just build them everywhere? I think any conquered Capital City should be knocked down to a Colony Capital. You clearly have some code to re-designate another planet a civ's capital, so if a civ loses its capital city it should be easy to just bump the re-designated Colony Capital up to Capital City to compensate. Or do you do that already? I haven't checked.