Burai Fighter Deluxe for Game Boy runs at different speeds in the US and Japan versions

I was really surprised to find out the US release of Burai Fighter Deluxe for Game Boy was slowed down significantly compared to the Japan release!

I quote the review by GouldFish On Games:
Budget Game Review: Burai Fighter Del...

The background music is from "Stage 1 and 4", from Zophar's Domain.
https://www.zophar.net/music/gameboy-...