You know the game is good when fish swim up into the sky! 😁 I like the idea of a game a lot: it's quite unique.
It was simple to understand basic game mechanics and I think puzzle progression is fairly balanced. I got stuck on level 21: one red fish didn't leave the area despite facing towards the edge of the screen. I think that's a bug.
Some levels are a bit too easy and even have unnecessary weights but most puzzles are good.
Great job! Good luck with your future projects!