Hard fish is a version of the fisherman mini-game that allows Jak to play the mini-game after collecting the fisherman power cell. By inputting Left, Left, Right, Right, Left, Left, Right, Right, X after you collect the power cell from the fisherman, a "Press O to talk" prompt will appear. Pressing the O button will allow Jak to play a much more difficult and endless version of the fisherman mini-game.
To activate hard fish, you must first complete the "Catch 200 pounds of fish" mission. After you've done that, stand next to the fisherman and input Left, Left, Right, Right, Left, Left, Right, Right, X on the controller. This will bring up a "Press O to talk" which allows you to talk to the fisherman and play the hard fish mini-game.
Hard fish was discovered by Dass on June 5, 2021.