Sonic CD

Level Select:
While at the title screen press Up, Down, Down, Left, Right, Space. 

Note: Only a single level may be completed each time with this feature enabled. 

Development Team High Scores:
While at the title screen press Right, Right, Up, Up, Down, Space. 

Cheat Mode:
To enable the sound test screen and chat mode press Down, Down, Down, Left, Right, Space at the title screen . Enter and play one of the corresponding sound combinations to activate the corresponding cheat function. 

Function                        Sounds
---------------------------------------------
Debug mode                      - PCM12, DA11 
Bonus levels                    - PCM07, DA07 
Display artwork                 - PCM03, DA01 
Human-faced Sonic               - PCM12, DA25 
Hercules Sonic                  - PCM04, DA21 
"Revenge of the Mutant Artwork" - PCM11, DA09