Thanks for the quick response! Steam Deck runs on a custom Linux OS. Anyway, it turns out I just can't read 😅
I ran the game with Proton and it booted up and played fine, however, Linux doesn't normally support MIDI files, and it seems to be a nightmare to make it do so.
After struggling for hours to figure that out, I finally realized that you literally wrote on your installation instructions to use EasyRPG Player. Once I did that, the game played perfectly and the music worked as well.
Thanks again for your response and thank you for your hard work on the translation!