I liked the art and music a lot.
The tip to lure in more fish by clicking was a fun twist to discover how the mechanic actually worked but it would have worked even better if it was told in the game instead of the project page.
I've read your submission comment and immediately stopped to check out the page otherwise I would have totally missed that.
I would not let the player go into the negative money. Getting back to 0 is usually worse enough.
There are some small annoyances like the eel spawning on top of the hook or some physics chain reactions that could be improved on when polishing the game further.
Overall quite an impressive project you delivered here.