Pirates and Crime
Space Piracy is a popular fantasy - we touched on it a bit with the Treasure Hunters origin in Grand Archive, but they could mesh well with the Nomads idea mentioned earlier or even a factional political expansion. Crime and Deviancy aren’t terribly engaging systems at the moment either, and might benefit from wider examination.
Warfare and War Resolution
At some point in the future, I’d like to see us revisit war and war resolution, and enable more of the scenarios that occur in the “Stellaris Cinematic Universe” of our trailers. When the Gamma Aliens attacked the UNE colony of Europa VII, the Commonwealth of Man did not wait patiently for an invitation to war before summoning the Apocalypse. Humanity was threatened, and they acted. More fluid rules around joining and leaving wars are needed, and betrayal is not supported to my satisfaction. (Secret Fealty exists, but I don’t find it enough in its current state - other mechanics currently prevent them from seizing the chance for freedom at what would be the most opportune moments.)