Great game! Reminds me a lot of the Pokémon ranger games which I loved as a kid. The graphics look nice (especially the water), the sound were good, and the game loop is very fun already!
I think one thing the game is missing is some better feedback with more bite to make it a bit more satisfying. For example, I think it would cool if the fish blinked red and shook a bit whenever they get damage by the lasso. Additionally, I think it would be better if you only had fish spawn from outside the screen and have them move into the play area. The fact that they spawn in the middle of the visible screen makes it look a bit choppy and more importantly can make it unfair to deal with - I had fish spawn directly in my lasso causing me to lose one without any way to prevent it. If you have them spawn inside of the screen you need to make sure to disable their collision for a short time after spawning to mitigate that - and maybe you could add a spawn animation like in one of my previous jam games shroom.