This small program allows you to export/import save data as JSON files.
⚠️ Use this program at your own risk! I am not responsible for loss of save data. Back up your saves before messing with them!
First, you need to get the encryption keys from the game. You can do this however you want – the main program accepts them as hexadecimal strings – but I've built a simple plugin/mod that works under both BepInEx and MelonLoader to make things easier.
Download the latest build of the plugin for BepInEx and extract the DLL into the BepInEx\plugins folder inside your game's install folder. Note that you must also have JSON.NET (Newtonsoft.Json) installed – if you don't, download the latest release and put Newtonsoft.Json.dll in the BepInEx\plugins folder.
Download the latest build of the plugin for MelonLoader and extract the DLL into the Mods folder inside your game's install folder.
Once the mod is installed, simply launch the game and a new file called SaveEncryptionKeys.json should be created in the game's root folder.
Download the latest version of the program and extract it wherever you want. You may need to also download and install the .NET Desktop Runtime 5 for the program to run properly.
When you run it for the first time, it should automatically detect the location of your saves. If it doesn't, you will be prompted by a message asking you to locate them. They are usually in the folder C:\Users\<your username>\AppData\LocalLow\Schell Games\UntilYouFall. Make sure you select the UntilYouFall folder and not one of the folders inside it!
Once that's done, press the "Import Key & IV..." button to open the file generated by the mod earlier. It should fill in the "Encryption Key" and "Encryption IV" boxes.
Values in the save files are stored as strings even if they are objects or numbers. The "Deserialize Values" checkbox enables/disables deserializing these values into their actual JSON representation.
Your preferences will be saved to a file called settings.json (folder/keys/checkbox) next to the executable.