Nice visuals and relaxing music!
I love your game's idea, but the bugs really spoil the fun. Sometimes the aquarium crashes without having an apparent collision. Sometimes, the player will end up in the void (pressing R to restart alleviates the frustration, but it still bothers). Getting trapped in a dead end without can do anything doesn't help either...
Despite theses considerations, the beautiful pixel art and the immersive music keep me playing your game longer than I thought ❤.
Overall was a good experience! Good job!