Wow, you really nailed the dreamscape vibes; the ambiance was so wonderfully weird, I loved it.
In my opinion, the lore was the strongest aspect of this game, and I hope you expand on it after the jam. It has the potential to develop into a beautiful story you’d find in a book. Every animation and the background movement really brought the game to life and added to the weirdcore vibes. I also really loved the big eye-fish-creature-thingy, which added flavour to the beautiful world design.
As for the gameplay, my main points of feedback align with what other comments have mentioned (water vision, mermaid playability, etc.), so I won't delve too deeply into those. Playing the character felt nice, but I do think some kind of light combat system could work well with this game. As it stands, the gameplay is a bit lacking, but I hope you don't get discouraged and continue expanding the game—it's a game you should be proud of. If you plan on expanding it, let me know, and I'll definitely keep an eye out for it even after the jam.