The whole soundtrack is cozy and cute, I love the funny sound design and would love to play a game with this OST :)
The tracks that are the most captivating for me are: Queen Bubblene Blast (the melody is so catchy, I keep on humming it after listening, the vibe of this track is cool), So You've Been Turned Into A Bubble (the bright sound of the piano here is so nice) and Octo-Popper Supreme (absolutely love the jazzy vibe) :)