Wow... here we are on a high level. The idea of bubbles in the main theme is beautiful.
Writing that I truly adore. Minimal, with a touch of nostalgia but at the same time not empty: in the background, there are many elements that prevent the music from being static. The music also fits well with the concept of the game, and all the tracks have an evident common thread, which is not a given and not easy to achieve.
Really, best of luck with everything and may the best one win!