I was thinking that it could be kinda fun if hunting mechanics were expanded into the future eras.
On Earth, you could use subdued animals to uplift some species, either supplementing or replacing cultures like Cetacean sapiens.
Then in the stellar, Orion Arm, Galactic, and supercluster zones you're basically "hunting" for primitive, modern, K1, and K2 species/civs respectively. The uplifted/subdued forms could add cultures and other buildings, or upgrade to settlers, workers, or military units. Or you could eat them and harvest their planets, if that's what you're into.
By the Observable and Distant universe, you're probably hunting space whales, crystalline entities, and other, lesser god-beings.
Spawning would probably have to be reduced to accomodate life seeding, though I don't think it's exclusive, and perhaps you seeding life could actually lead to these species spawning.
I know the space stuff is relatively low priority for development, but this would add a combat element to the very late game in lieu of, or perhaps in conjunction with having barbarians or actual NPCs in space.