You have the foundation for what could become a really great game. I genuinely enjoyed the art style and the music - they both feel like they were made and chosen with a lot of care. I also wanted to point out a few small things that caught my attention. Please don't take this the wrong way - these are just a few minor details that I think are worth looking at.
The first one is the fish shadow while you're fishing. When the fish changes direction, its shadow doesn't flip, so it ends up swimming tail-first. It seems like a tiny detail, but it actually makes the fishing feel a bit stiff. Simply flipping the shadow sprite when the fish turns would make the animation look much more natural.
Another thing is the patch with the cross on the backpack. I kept instinctively thinking it was the button to leave the scene. At one point I even thought the game had bugged out until I accidentally clicked the tag instead. The actual tag blends into the background quite a bit, while the cross patch immediately draws your attention, so it's easy to mistake it for an interactive button.
Buttons like "Start Sift" also feel a little too small and blend into the background, which makes them easy to overlook. The hover effect helps because they darken when you move the mouse over them, but I'd still suggest making them stand out a bit more.
Alright, I won't bore you with any more tiny details :) Good luck, and I wish you the best with this awesome game