I greatly appreciate the detailed responses and mini-walkthrough for the game.
I believe that you could just put the game through 'machine translate' via Google Translate or another free translation service. It wouldn't be perfect but it would be better than all German.
I'm already multilingual with English, Spanish, and some others. German isn't too high on my list as I don't encounter many times where I'd need it ;)
I'm sure if you put up a crowdfunding page then you could raise like $500ish or so to hire a professional translator and possibly put the game up on Steam once it is fully translated. You have some interesting game features so hopefully it would be good to try.
Feel free to join my FreshGaming Discord community server. We can talk game design and other bits if you want ^_^