Nice game! I did not expect a Super Mario Odyssey-esque game using the mouse to control a mass of fishes. Quite original!
The dialogues are a nice touch, as hints are given through them. Adds a lot of personality to the game. The puzzles are simple, but fun.
Be careful designing such large rooms. I didn't like the swim in the middle, where nothing happens without any indicator of where you are. I suggest splitting this big room into multiple little ones, or maybe zooming out further you are from the sides.
I enjoyed it! You can be proud of your work.