Beaver city builder Timberborn has just gotten its first major content update in Early Access, which gives those adorable semiaquatic rodents a chance to wade deeper into the dregs of humanity’s remains, and some more literal dregs in the form of mud baths. The update also breaks compatibility with old saves, so you’ll want to be careful before bringing in your old saves.

“Once you update the game on the main branch, existing saves become largely incompatible, as indicated by a warning,” the devs explain. “Please start a new game! If you want to continue building pre-patch settlements without the new content and changes, we have added a pre-patch branch called ‘Old version 0.0’. You can access it the same way you enable the experimental branch, as explained here.”

Underground ruins aren’t the first remnant of human civilisation we’ve seen in Timberborn, but they’ll provide an infinite source of scrap metal, as long as you’re able to build mines to claim it. Then there are the mud baths, which will help your beavers enjoy a little R&R.