Only just remembered that Fishing Jam was on, so this was Day 1 for me.
I'm planning to make a puzzle game where you have to hook all the fish in the level to win and you reel them in one at a time. You have a maximum reel/line length and reeling in certain fish / sea creatures will impact the level. For example there could be a weak blockage that you can't pull fish through, but if you pull a hard crab through it the blockage will break, giving you a shortcut and allowing you to reach more of the level with your limited line. Another kind of catch could leave an impenetrable trail behind it (squid ink maybe?). So the goal is to work out which order to reel the fish in and what route to reel them over, with the additional constraints of a limited length of line and the fact that the line can't cross itself. We'll see how it goes!