I'm posting the Polish translation of the game here. It will certainly be useful to many players.
How do I change the language?
1. Download the pl-PL.zip file
2. Unzip it
3. Go to the game files: steamapps/common/RisingWorld/data/StreamingAssest/Languages
4. Upload the unzipped file
Now change the language to Polish
The best way is to change it in the game's configuration files.
steamapps/common/RisingWorld/NewVersion/config.properties
Line 478
If you're playing with language mods or the Steam option isn't working, you can manually edit the files:
1. Navigate to the game's installation folder on your hard drive.
2. Open the config.properties file using any text editor (e.g., Notepad). Line 478
3.Find the Game_Language line and replace the desired value, e.g. Game_Language = pl-PL (just like the name of the downloaded file).
4. Save the file and restart the game.