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 "archive_branch".
- 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