Over the past few years, I've been making a SNES-style soundtrack mod for Cave Story+ with OpenMPT in my free time. Since all of the songs are finished now, I was able to successfully convert the exported FLACs into seamlessly-looped Ogg Vorbis files, which the game engine can play back. However, when you hear it change from song to song in-game, it sometimes feels like some of the songs are too loud or too quiet in comparison to each other.
I'm surprised that this is happening, since I made sure to click Normalize Output on every export. I don't know much about mixing and mastering, or if those terms are even appropriate in the context of tracker music, but does anyone have any experience with this kind of issue, or know what I should do to further even things out?