elevators would be wayy too advanced for the theme for this game. An automatic purifier however seems interesting. I wonder how it would work.
I proposed an idea of using sea turtles to capture drinkable rain water (totally stolen from The Forest) or something primitive. Think Gilligan's Island, but I agree there shouldn't be an overly complicated mechanical system here. You're stuck in the middle of nowhere with next to nothing on your back. You're not MacGyver.