Demo has been updated to v1.21. Which includes all balance changes and translation to several languages.
Note that this makes old saves incompatible. If you wanted to finish your old game in progress, here are instructions: https://www.silverlemurgames.com/2024/06/04/legends-of-amberland-ii-demo-updated/
This also means that all new saves can be imported to the full game. Just copy saves from "C:/Users/YOURUSERNAME/AppData/Roaming/Legends of Amberland II Demo" to "C:/Users/YOURUSERNAME/AppData/Roaming/Legends of Amberland II" (the exact path might differ depending on OS used).