Simple and short guide on how to import your saves from the demo to the full game on Steam Deck and Linux.
How
In desktop mode, you need to copy the save files from the wine prefix of the demo (1690940) to the wine prefix of the full game (1671210).
Commands
If both the demo and the full game are on the internal drive (default), you can simply paste this into your terminal (Konsole by default):
cp ~/.steam/steam/steamapps/compatdata/1690940/pfx/drive_c/users/steamuser/AppData/Local/DELTARUNE/* ~/.steam/steam/steamapps/compatdata/1671210/pfx/drive_c/users/steamuser/AppData/Local/DELTARUNE/
If one or both of them is on another storage device (MicroSD), replace “/path/to/” by the path that contains the right “steamapps” folder:
cp "/path/to/steamapps/compatdata/1690940/pfx/drive_c/users/steamuser/AppData/Local/DELTARUNE/"* "/path/to/steamapps/compatdata/1671210/pfx/drive_c/users/steamuser/AppData/Local/DELTARUNE/"
The first path is the demo, the second is the full game.
It won’t overwrite saves for chapters other than 1 and 2.