Oh yes, it's time for soundtracks with epically beautiful covers!
The main theme is Heh, sounds like a good muse. escort to some futuristic underwater city of fish)
Vendor Theme theme sounds like an interesting night theme. Imagine: the night streets of an underwater city. Flashlights, glowing teenage fish who want to escape from their parents' house, and a couple of sleepy fish who are not allowed home
The battle theme is a very groovy theme (I danced to it) It's a very interesting idea to make a mix of jazz and... a fish synthesizer?)
The final theme - Well, how can you do without the melancholic ending of the soundtrack with notes of happy dynamics? No way! And you did it perfectly)
Good... It was one of those soundtracks that I shook my head to. Cool!