If you would like to access a save file that requires an older, archived build of the game, your game version can be reverted by changing your branch. To do that, follow the steps below:
- In Steam, click on Library > Games.
- Scroll down to Oxygen Not Included.
- Right-click and select Properties.
- Go to the BETAS tab.
- In the dropdown, select the name of the branch you want to play.
- In some cases you may be given a password to unlock the appropriate branch. If this is the case, paste that password in the box below the drop down, submit and your branch will now be in the dropdown menu.
- In that same Properties window, go to the Local Files tab and press "Verify Integrity Of Game Cache."
- Your game will be updated to the the previous branch.
- Launch and play Oxygen Not Included