Hey Fabian,
I don't know any german but according to Google Translate you said:
"I do not know if I should write in German or English. I am a German. So I have read the mail. But it still does not work. There is always an error warning as I wrote in the comments. I would love to play the game but it does not work ... I hope their team can help me somehow. Best regards"
Could you be a little more specific on your computer are you on Windows, Mac, or Linux? are you on the itch.io application or standalone? Did you try extracting the Zip file onto your desktop? Maybe theres a free space issue?
Hope I can help you out,
Rafi
Google Translate:
Könnten Sie ein wenig spezifischer auf Ihrem Computer sind Sie auf Windows, Mac oder Linux? Bist du auf der itch.io Anwendung oder Standalone? Haben Sie versucht, die Zip-Datei auf Ihren Desktop zu extrahieren? Vielleicht gibt es eine freie Raumfrage? Hoffe, ich kann dir helfen, Rafi