@kazuuu
You could install a port from the setup script and it’ll create one for you at /home/pi/RetroPie/roms/ports. I would assume you could just create your own folder there but not sure if there’s anything else that would need to be created for it work? Installing from the script would make sure everything was made and you could always delete the other game after the folder was made.

@hiulit you can even create your games on the Pi with these unofficial Godot builds https://github.com/hiulit/Unofficial-Godot-Engine-Raspberry-Pi