Wow. I was expecting a basic cute fishing game. What a pleasant surprise!
The double theme interpretation is ingenious. I have to give that a 5. The story was really well executed with each section feeling fluid, and of course a solid climax. In terms of gameplay, I like how you forced the player to pick up the story objects in order to progress the upgrades so that they can't miss the storyline. Also the gameplay itself, simple as it is, was enjoyable and very well paced. A great example of how simplicity makes for a great jam game.
Also, one of the comments said this is your first jam game!? Really really cool, my(and many others') first jam game was nowhere near this level of quality.