I was thinking earlier today how neat it would be if you could play as a nomadic species among the stars with no real home world. This can somewhat be done with the space biomes but if you stumble across a giaworld then congrats your search is over. It would be an interesting challenge if that wasn't the end. If say there was a new origin where for one reason or another these spacefaring nomads can no longer live there. This could be for several reason. The planet could be shattered, taken over by a hostile empire, robotic revolution displaced organics, or turned into a toxicworld by pollution. Whatever happened they won't be able to go home for a long time and could even be an event chain for later in restoring or reclaiming the homeworld. The real problems would come in what to do to replace planets. Well what if instead of having population contribute to fleet capacity have the size of your fleet determine the pops you can support. To substitute districts and buildings the flotilla could make a civilian fleet that provides the jobs like research, energy production, and mineral refinement while also changing how many military vessels are made before the civilian fleet can no longer provide. It would also mix-up warfare as instead of capturing a starport and bombing a planet to the stone age or landing armies one would have to chase down a moving target that while large health has little military capacity and when damaged destroys industry and pops of the nomads. There could also be certain treaties a nomad could sign with another empire to make a environmental shelter on another's worlds similar to Megacorp's branch office system for a boon of fleet cap, minerals, or other resources.