You fish as u did normally before, but now your rod leans to a side, you must push your character in the opposite direction. So if the rod goes left u hold right, if it goes right u holdleft. Now If your rod is in the middle you either hold forward or backward to stop the fish from regaining HP( i cant remember which). If you let ur rod go into the same direction as the fish it will regain HP. It is best to reel in your catch when the fish has no HP. But be aware it may change directions right as your hit to reel it in. If it does this you may lose your catch.