itch.io

What are you talking about? You can get the game here on Itch.io even if you live in Germany. I just bought it. But the dev can (if he is that nice, that is) provide steam keys for the infantilized germans.

its not credit card its  because the Developer probably didnt fill out the formal document or it was flagged because of the adult content when the document was filled.    Valve needs to  restrict it in both cases (when it gets flagged or when not filled out correctly)    in germany due to law restrictions on goverment side because Valve dont want to add proper age verfication