The 15 Puzzle is a secret minigame in the original Final Fantasy that can be played after having obtained the ship; the player must hold the button while in the ship and press several times until the game appears. It exists in nearly every version of the original Final Fantasy.
In the puzzle the player must organize 15 squares into numerical order by sliding the squares. After solving the puzzle the player receives prizes, such as money and items.
In the original NES version the reward for completing the puzzle is simply 100 gil. In Origins the prizes are better, including: