Thank you for the report!
German localization was prepared but not released yet. It looks like the incomplete localization was falsely loaded when starting the game on Windows with the German system language. A new version of the game was just uploaded and should fix the problem!
Please use the “Reset Game” button in the settings dialog to restart the game save. That would be "Spielstand Zurücksetzen" in German. After that, it should all work correctly for you, but please let me know if you encounter an issue again.