I love the simple pixel art style you went for, the outlines are just great sometimes!
It was fun trying to fit all the fishes together :) There are a lot of them I see.
Alright, so:
1- The fishing system is really satisfying, a two part system consisting in moving the hook to get the fish you actually want and then fighting with the fish to get him out, I love it!
2- I really like every single sprite in your game haha. Every fish looks great and that final...creature (queen?) looks amazing, with a very cool animation
3- It's really cool that you have a leaderboard at the end. I don't know how those work but it's just great haha
4- You found a very interesting way of combining the inventory system with an interactive sort of puzzle where you have to fit everything (Again: just great job!)
*(For improvement) The only thing I can say is that the game could use some music and sound effects
Overall a great job that deserves more attention !! (5 stars in every aspect)