At the title screen, select Options. Highlight Sound Test then play the following music and sounds: 19, 65, 09 and 17. You will hear a ring-collecting sound for correct code entry. Then press START to return to the title screen. Highlight 1-Player, hold the A Button (defaults to the Y button on 3DS) and press START. You are directed to Level Select Screen. Choose a level then press START to begin.
| Code | Effect
|
|---|
| 17 | Play Invicibility Music.
|
| 65 | Plays a Shifting Sound.
|
| 09 | Plays Casino Night Zone 1-Player Music.
|
| 19 | Plays Sonic 2 Theme.
|
