Place a Chao in the VMU and change its name to the following:

Beat the rest of the four courses. Note: Don't delete your your chao data or else you will have to do them again.

While playing with Sonic in Casinopolis, go to the pinball game with the NiGHTS motif. Hit the three little purple point givers in order to open up an entrance at the top of the board. Then make your way through the secret entrance. You'll now be in another NiGHTS motif pinball game. Whenever you fail to catch Sonic with the bumpers, don't worry about losing a ball. Instead, Sonic will be transported through a world very familiar to the NiGHTS level Splash Garden. You can even see NiGHT and pians!

Press X immediately before entering the snowboarding portion of the game to get a blue snowboard or B for a yellow snowboard.

You can find some cool hidden Sonic Adventure arts made by SonicTeam themselves by putting the GD-ROM inside the computer's CD-ROM drive. Access the folder inside it and view the .bmp pictures there!

Pause the game and hold X + Y to clear the game of the pause screen.

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.