Just a heads up for everyone: The local co-op is enabled in the staging branch. We'd be thrilled if you give it a spin and send us feedback. We'll keep it in "staging" branch for some time to iron out the kinks, so if you want to try it go there. The local co-op should be fully functional via multiplayer buttons at campfire or at main menu.
Learn how to use the staging branch here: https://steamcommunity.com/app/2430390/discussions/0/801215926447939113/