This TRPG is really astounding. It took me a few days to get through it all, many of the sections need time to sit and digest with you.
As someone who has never fished in a meaningful way, it is hard for me to picture how to make the fish combat exciting without immediately falling back into the outlandish and goofy, though eventually that's where you'd want to take the game with the nature of the mid level fish (I adore the concept and art of the Panfish). The combat and story tools feels straightforward, as it was designed to be. A quest to capture a legendary fish is a one track plot, and the doubt of 'is it magical are not?' are irrelevant when players have to catch it to win.
The number of fishing techniques and limited variety in types of fishers were a little disappointing too, I would have loved to see more, and more mechanics to support solving problems beyond fighting on land or water.
But when I was doubting the game's variety, I was blown away by the sheer creativity of the settings, play options, and adventures. It's a wonderful showcase of all the ways you can twist the system into something new, easily packed with replayability and originality. The bestiary and fishiary is so rich with fresh ideas, it makes me wish that the fisher types and techniques could have had that level of detailed description.
With the volume of settings and modules, there really is something for everyone here, no matter how little you think of fishing. Even if just using this TRPG to fuel your D&D5e beach episode, you won't be disappointed at all. In fact, prepare for that game to take a new direction after you introduce a little Rod, Reel, & Fish into it.