Thanks for the report! All music were taken from Jamendo.com and all of them are under CC. The battle music is Adventure by Celestial Aeon Project (https://www.jamendo.com/track/818620/adventure). Perhaps it was licensed commercially? Either way I think you can leave it flagged. But it's weird because someone else made a video about it but it didn't trip up the copyright detector.
Ah, that is pretty easy to fix. I'll see if I can update the game sometime soon. Thanks!