Some really great graphics and cool ambience !
The game design is overall great, I guess User Interface could benefit from some help (like information on the attacks when the mouse is over it, or information of the type of fish that comes out of the bubbles and the number of cases it will be able to make).
I found myself using a lot of the "return" button but most of the time because the "default" option was not moving, and I ended up wasting my attack or even attacking my other character. I think the default option is the last one made but I'm not sure.
Concerning the iterations you could make from this game, I guess variety from fishes or even level design elements could benefit from a longer experience.
However, tested it on late september 2021, this game was enjoyable :D