Development:Sonic the Hedgehog CD (Sega CD)

This page details development materials of Sonic the Hedgehog CD (Sega CD).

In 2013, Christian Whitehead released some unused Sonic CD sprites, intended for the scrapped level Dubious Depths ("R2"), that were leftover in Sega Digitizer files. Whitehead was given access to the files when developing the game's 2011 remake, and stated that these were the only remnants of Dubious Depths he had access to, as "very little" of the stage remained by that time.

The sprites include three of the normal enemies that were to feature in Dubious Depths, as well as the round's boss.

(Source: Christian Whitehead)

Sprites

Artwork	Name	Description
	Burrobot	The first of the three normal enemies that the player would have encountered in Dubious Depths is a drilling robot. It is named Burrobot on the sprite sheet provided by Taxman because it appears to have had similar, if not identical behavior to the enemy from the original Sonic the Hedgehog (jumping out of the ground before walking forward). It appears that the deteriorated variant would have had damaged and bent drills.
Base Alt.	Antlion	The Antlion is the second of the three enemies in Dubious Depths, and the only one with a known name. It does appear in the final game's Pencil Test and the uncut version of the ending animation, in which one attacks Sonic. Based on its depiction in that, as well as concept art, Antlions would have burst out of the ground through sand traps when the player ran over them. Antlions were also considered for an appearance in Metallic Madness (presumably after Dubious Depths was cut). This variation was redrawn to slightly reduce its size and give its body a rounded shine more consistent with the artwork for other enemies in the game. The sloped pits in Metallic Madness appear to have been designed with Antlions in mind, prior to their removal.
	Worm/Snake?	The last of the three normal Dubious Depths enemies is a robot resembling a worm or a snake. Like the other two Dubious Depths enemies, it appears to be an enemy that would burst out of the ground. A deteriorated variation of this enemy also exists, showing it with exposed wires and drooping eyelids.
	Boss	The boss sprite depicts Eggman riding an Egg Mobile with a giant wheel on the bottom and a spring on the back. It's somewhat similar to concept art showing Eggman in a wheel with a chainsaw attached to the front. The sprite appears to be unfinished, with the wheel in particular lacking detail.