Ruin is now known as Macabre.
Your saves will remain intact, but you will need to rename your save folder and the actual save file(s) to macabre instead of ruin.
On Steam, right click the game in your library and go to properties. Click on the browse local content button and it will open up the file directory.
From there, navigate to the ruin.saves folder on Windows, or the saves folder on Mac/Linux. Replace “ruin” with “macabre” on both the save folder itself AND the save files inside (.rsav extension). After doing that, your saves should work properly in-game.
I apologize for the inconvenience that this has caused. If you run into any issues, please let me know.