This was a great game. Art and animations are very well done and the sound track was really relaxing to hunt for fish by. My one major suggestion would be to add a better explanation as to how to smushify. I found out by accident by making one last random check of the window that you smushify by checking the window to see if one of your fish is in the slots. (Possibly edit the instructions to say something like "Check your Smushify window every time you catch a new kind of fish to see if you have the right combo for a rod upgrade.")
Remember to eat your fish kids, it's good for your stats :)