Sonic CD (Sega CD)

Sonic CD is just your average Sonic the Hedgehog game on a CD... that's what you're told, anyway.

Level Select
Press Up, Down, Down, Left, Right, B at the title screen. Note that you will be taken back to the title screen upon completion of the selected level.

Sound Test/Debug Mode
At the title screen, press Down, Down, Down, Left, Right, A to go to the sound test. By entering the following codes, you can get the corresponding image, debug mode, and/or extra after pressing Start.

Unused Special Stage


As mentioned above, setting all three Sound Test selections to 07 will load this stage that features the enlarged head of Eggman as its background and has a rather difficult layout. It's possible that an extra Time Stone was to be collected here at one point, though it's probably just a little bonus thrown in for curious players, much like the hidden pictures.

Regional Differences
Almost the entire soundtrack was redone for the American version by Spencer Nilsen because Sega of America thought the soundtrack of the Japanese and European versions sounded too identical to the electronic dance soundtracks being produced at the time, so the American soundtrack has more of a rock feel. One example of this is the theme song: instead of "You Can Do Anything", the American version has "Sonic Boom". The only songs that weren't altered were the Past themes, since those were played through the PCM chip and not Redbook.

In addition, there are a few other differences in the American version compared to the original Japanese and European games:
 * Some of the music placement was switched around. For example, the "Little Planet" theme now plays on the Time Attack screen (rendering the title theme copy unused), and the music played during the Metal Sonic race is now the normal mix of Stardust Speedway's current Future and not always the "B" Mix.
 * The player can restart the stage at any time by pressing a button while it is paused, eliminating some potential time warp issues. This is at the cost of one life.
 * There are no longer sound effects at the beginning of the ending. Due to the extended "Special Edition for North America" credits, the ending theme plays over the entire video and mutes other audio (including the post-credits).
 * The bad ending's "TRY AGAIN AND SAVE LITTLE PLANET FOREVER" text was shortened to simply "TRY AGAIN".
 * The special "YOU ARE SUPER PLAYER" screen now includes "A" to remove Engrish.
 * The copyright text at the title screen was altered slightly.

All of these changes are also in the PC version, though the 2011 re-release reverts the Metal Sonic racing theme so it always plays Stardust Speedway "B" Mix and mostly restores the original ending videos' exclusive audio when played with the Japanese soundtrack.