Every track is in the credits, and can likely be found on Youtube. Feel free to ask me if you want to know where any specific track is.
Yeah, there are a lot of cool characters that I wish were developed more. My main philosophy for making MG1K characters was to make them interesting enough to be the protagonist or "main girl" of their own game, and while this certainly led to a lot of deep characters, it also led to a feeling of wanting more from every character.
My biggest lesson from MG1K is that this type of quantity over quality doesn't work. Having 20 characters with 20 scenes of development probably isn't as satisfying as having 5 characters with 4 scenes of development each.
What is the name of the music that plays during the rescue of the characters we met throughout the game after the final battle with Eris, and during most of the post-game battles in the colosseum?