I beat the final boss. It's one of those ones where you unlock the next cutscene each time you finish it. Apparently have to beat it like 8 more times to see all endings but the gameplay isn't any different so yeah I'm not doing that. It was fun, the mutations and the way it changes your character model is interesting, but it wasn't finish the game 8 more times interesting. So although I can't say I'm technically finished, I feel I've seen everything it has to offer so I'm done with the game.