Requires a Nintendo DS + Flashcard or an emulator

Intro and Background


What works

What Doesn't Work

Usage Notes

Usage Instructions


This is a Proof-of-concept made by myself in late 2009 and early 2010 while collaborating with Christian Whitehead in creating his Sonic CD remake prior to its formal acceptance by Sega. Before Sega's iOS poll, which provided the perfect opportunity for him to accomplish his pitch, I was contacted by Christian and commissioned to do reverse-engineering and documentation work to help in getting a stronger build prepared for making his case with Sega

Primarily, I was to dissect and explain the Palmtree Panic Zone boss, which is pretty complex in design by comparison to how effortlessly it can be beaten, so that he could reproduce it flawlessly. During this time, I personally reconstructed the boss myself using my existing port of Sonic 1 to GBA/DS to make certain that I was understanding it correctly. At the same time, I also had a personal interest in Sonic CD's Special Stage, which I had also been dissecting, and continued my work with it in order to both provide assistence (though not direct) with Christian's Sonic CD build, and to attempt my own with the DS

As both projects continued, I saw merit in the idea of pitching the concurrent development of a DS version of the game, which would require such a low-level remake as mine due to the fact that the DS wasn't powerful enough to support a scripting-based game engine like Retro Engine. Given that, I set out to make a complete POC, which was taken pretty much to completion

Unfortunately, once Christian's version was formally accepted and he was under contract, I would no longer be able to associate with the project and was therefore without a means to get the concept off the ground. I had no other contacts, and with this being Christian's first project with the company, he understandably couldn't take the sort of risk that would have been involved in attempting to take care of it himself

Other inhibiting factors would have included the fact that Sega was moving toward digital distribution, and a DS version of Sonic CD would have absolutely necessitated a cartridge. The audio quality would also have to have been sacrificed, which may have been another factor. It also wouldn't be long before the DS and DSi gave way to the more powerful 3DS, and with Christian's Retro Engine already on-hand, this particular project was no longer of any commercial use, and therefore was cancelled permanently

The project has since collected dust, and is now being presented as-is for the sake of novelty. It can not and will not be continued. Most errors are known and reports are not desired; there will be no updates


Sonic Team/Sega are responsible for the original Sonic CD game reproduced here
The majority of the work that went into this project was performed by me (Stealth -
This project uses MaxMod ( for audio
The module music used in this project was set up by me, and is just downsampled audio tracks duct-taped to mostly do-nothing XM data


 General -
-Title Screen and Menu
-Level End Sequence
-Animated Tiles
-Invincibility, Sneaker, and shield powerups
-Time Travel (Activate time post and run at full speed for a few seconds)
-Palmtree Panic Zones 1-3, all time periods, all objects, including boss
-Special Stage with entry from big ring (appears at level end when you have 50+ rings)


-Basically anything that wasn't listed in "WHAT WORKS"


- Copy the main "SonicCD" folder (which contains "Player", "R1", etc.. subfolders) to the ROOT of the SD card. It will not work from any other location
- Place SonicCDDS.nds anywhere on the card
- Run SonicCDDS.nds

No$GBA (Recommended for emulation)
- Run SonicCDDSFull.NDS

DeSmuME (Not recommended)
- In the "Emulation" menu, select "GBA Slot", and from the dropdown menu that appears, select "MPCF Flash Card Device", and then click "Use path of the loaded ROM"
- Ensure that SonicCDDS.nds is in the same folder as the main "SonicCD" folder. Do not put it inside the "SonicCD" folder
- Run SonicCDDS.nds
- This emulator exhibits a lengthy delay before the initial disclaimer screen appears
- This emulator exhibits a noticeable stall when the music changes
- The Special Stage runs at half speed when played in this emulator


 Main Menu

Navigate through options using up/down on the D-Pad
Change most options by navigating to that option and using left/right on the D-Pad
Change the selected game by navigating up beyond the "Title" option and using left/right on the D-Pad
Change "Round" by using A/B, X/Y, and L/R to change each individual component
Select an option by pressing Start


Use the D-Pad to move, and A/B to jump
Use R trigger to toggle Debug Mode. While in Debug Mode, A and B become object cycle and placement