Hi so I had a thought that I'll outline here what if we had the ability to play an hivemind/ sentient infection.

1) The INFECTION: (ALL ABOUT STEALTH- being detected by a star-faring power could the the doom of this species) Starts with stealth tech and uses ships to land infected troops on other planets to begin taking over via time and events to spawn armies over a few years this consumes infected pops.
- it doesn't cant' make ships normally instead is uses decisions/ edicts to convert infected pops into ships based on the traits (ie: very strong might net a battleship or titan)
-unique megastructure to land giant eggs (asteroids) on planets for giant creature mutant armies of giant creatures.
-upon taking a planet over, all remaining pops are slowly assimilated. Once this is done the infection takes control of the planet and slowly transforms it into into an INFECTED /INFECTED world.
- They can't make pops on any planet aside form their homeworld and stage 2 infected infected worlds.
-Infected worlds are part of the hivemind with a central organism controlling the planet and overseeing its takeover. If it dies this hidden pop and all infection armies are destroyed.

2) Defence Force: This once pre-FTL civilisation managed to eventually beat defeat the infection by terminating its link to its homeworld. and seeks it's interstellar origin point. First however they might need to convince the galactic community there's a sentient single celled organism that needs to be dealt with.... a tall order.

3) Exodus Project: This speices starts on their moon or orbital habitat above their species homeworld that is undergoing infection attacks. Most of their speices has been infected and or killed by this point so they need to find a new planet to evacuate to. Alternativly they could find main infected hub on the planet and defeat it allowing them to rebuild.