I think the fishes could kinda "telegraph" a bit more, but of course in subtle ways that they are about to just, would make this both a strategic decision which fish to go closer to to wait their jump but also help people decide the path of which sequence of fish would add more score ... that would also allow more complex scenarios perhaps

Very cozy game and what a fantastic art style. I'm not sure if the phases between frenzy mode has a role, I only waited for this funny moments. :-)

You asked for feedback on the itch site, so here are some thoughts regarding game mechanics that came into my mind. 

• it would be more pleasant if there is any kind of indicator that a fish will jump, maybe the fish starts to blink or there is a special animation
• fishes could give different points, but more points means it is harder to catch the fish, maybe because they fly faster or not so high as lower point fishes. That gave beginner players the change to train on easy fishes till they have the skill to get harder fishes for more points
• the frenzy mode feels to mighty, I mean it is fun, but the time in between is pointless, when I only try to avoid piranhas and wait for the time, where I don't have to react on a single flying fish and just run, getting points automatically.
• The movement of the piranhas is unpredictable, so dodging is imo impossible. Here an indicator is also necessary. I know that will make things to easy, but you can add seagulls from the top, which want to eat your fishes. So players have to look up and down for angry animals.

Overall really good job and very polished for a first single person made game. Keep on going.