Very cool concept! I love games with faux old school OS UIs. The checkbox system for enabling/disabling mechanics was a nice touch (and I learned some German). Had I not read the instructions and the details on this page, I probably would have assumed that was the end of the game after beating the first round. I wouldn’t have thought to check the mail... and maybe others won't. Maybe consider a “you’ve got mail” style alert or jingle to draw attention to it in a future version? Very polished though - well done! 👏