Hallöchen,
I really enjoyed playing this game. The Movement feels nice (WASD also works for movement which is great) and the fish cathcing mechanic also feels nice.
The Game Loop can get a bit repetetive, as you can just resort to spamming LMB. To Counter this, adding another kind of fish that you have to dodge and cannot catch would be a solution.
Also i feel like the Game would benefit a lot from sound and music. Add a Sound, that gives you Dopamine kick every time you catch a fish and some relaxed fishing music and you got yourself a way better game.
Overall, i liked the Game a lot, great job Guys :D