3D Sonic The Hedgehog 2 Level select
At the title screen, choose the “Options” selection, then highlight the “Sound Test” option and play the following sounds in order: “19”, “65”, “09”, and “17”. If you entered the code correctly, you will hear the sound of a ring being collected. Press Start to return to the title screen. Highlight the “1-Player” option, then hold Y and press Start to display the level selection screen.
Chaos Emeralds
Note: This only works as Sonic. Enable the “Level Select” code. Select the “Sound Test” option from the “Level Select” menu. Play the following sounds in order: “04”, “01”, “02”, and “06”. If you entered the code correctly, you will hear the sound of a Chao Emerald being collected. Choose any starting level from the “Level Select” menu. You can now turn into Super Sonic after 50 rings have been collected, as well as view Sonic’s second ending after completing Death Egg Zone.
Debug mode
Enable the “Level Select” code. Select the “Sound Test” option from the “Level Select” menu. Play the following sounds in order: “01”, “09”, “09”, “02”, “01”, “01”, “02”, and “04”. If you entered the code correctly, you will hear the sound of a ring being collected. Highlight any starting level from the “Level Select” menu and hold Y and press Start to begin the game. The following buttons can now be used:
- Toggle Debug mode: Press B.
- Cycle through objects: Press Y.
- Place selected object: Press A.
- Reset game: Pause the game, then press Y.
Completion bonuses
Successfully complete the game to unlock Ring Keep mode and Super Sonic mode.