You are here to assist the cat in his quest to catch as many fish as possible because they are hungry and you need to set sail by boat. To achieve that, use your mouse to control the cat's boat as it moves across the water. When you spot fish, click and hold near them to catch them, then drag back to catch them. Just be careful not to break the fishing line, or you will lose your fish.
Try your best to catch as many fishes as you can as you keep floating. Do you believe you can handle it?