itch.io

for some reason the file didn't want to start by double clicking for me either (also Mint), but I opened a terminal in the folder and wrote ./Ambermoon.net to start it that way and it worked :)

Edit: I now read you already tried the command line, so maybe this was a different situation (or you forgot the ./ for executing it)

A simple ./Ambermoon.net should do the trick. Don’t forget the “./” at the beginning. If this still doesn’t work, let me know.