I had an idea about a video game that might be cool, let me lay down the setting first or nothing makes sense: It would occur in a Dark Souls-esque post-apocalyptic setting, where nothing can die. The canonical explanation would be that something literally destroyed the afterlife, so the living world is 'dead' in the sense that nothing can die, and nothing can be born either, so everything that remained tore themselves to pieces over untold millions of years.
You the player would be placed into a suddenly sentient human homunculus, with the ability take the souls of defeated foes and implant them into other bodies and objects. No enemy can remain defeated if you don't capture it's soul, and one of the primary mechanics would be amassing a collection of other bodies, empty living vessels, and implanting the defeated foes into them so they can be pacified with a new purpose and lease on life. So, doing that, little by little you gather a community of these defeated enemies implanted into empty bodies, and you form a community that acts as your hub, ala Dark Cloud.
I'm thinking there'd be a secondary mechanic in picking and choosing which souls go into which bodies based on personalities, as some would be far more or far less competent at certain jobs, which is weighed against how happy some souls are in a given body and job. Example: One soul would be extremely competent at being a shopkeeper, but he'd hate doing it, and he may never improve at it over time, or you could place him into the body of a dog and he just loves it completely.
I'm thinking the object of the game would be to explore the post-death world, collect those few souls still sane enough to rehabilitate, slowly rebuild a functioning society, and uncover the truth about what caused the disaster in the first place. *idea in progress