You must have 3 controllers and the 3rd one must have a memory card for this to work. Start up the game with all 3 controllers plugged in and get into Adventure mode as any character. Now press START on the 3rd controller. Something on the memory card's screen will come up saying "CHAO PUZZLE". Press START again to begin. It is a 3x3 slider puzzle with a random animated Chao doing something for a picture. Use the D-Pad to select the piece you want to move and press A to move it into the open area. You can also move two pieces at once. Press B for a different puzzle. Press START again to quit. There are 15 levels and every 5 you complete there is a congratulatory message from a Chao. After you beat the 15th it will start you at level 1 again.