From Sonic Retro

Sonic Retro emblem.svg Sonic the Hedgehog CD
The level select screen in the Sonic CD 510 prototype shows every level in the game on one screen. Note the jump from "1" to "3".

R2 (or Round 2) is an unfinished level from Sonic the Hedgehog CD. Set to take place between Palmtree Panic (Round 1) and Collision Chaos (Round 3), it was removed at an early stage of development. Remants of its existence can be found in both the original Sega Mega-CD version of the game and its Windows PC port.

R2 is thought to be analogous to Marble Zone in the original Sonic the Hedgehog, with leaked concept art suggesting a stage that took place at least partially underground. Director Naoto Ohshima has claimed R2 was at one point called Dubious Depths[1]. Designer Masato Nishimura has confirmed this assertion, revealing the level was also called Ridicule Root during development[2].


Rainbow waterfalls and aqueducts, attributed to R2.
Little Planet concept, complete with "2R" design.

For many years, the existence of R2 was little more than speculation, gathered from inconsistencies in the game's files. Proof of its existence came in a Sonic CD developer's diary video, uploaded by Sega Europe onto YouTube on November 29, 2011 (to promote the 2011 re-releases of the game)[3]. In the video, a sketch of what appears to be rainbow-coloured waterfalls appears, something confirmed by 2011 port's lead developer, Christian Whitehead as concept art for R2[4].

With the release of Sonic Origins in 2022, further concept art was released, with mentioned of an "2R" level on a map of Little Planet, with the level order again suggesting R2 being located between (what looks like) Palmtree Panic and Collision Chaos. The art shows a forest of trees and what appear to be iron beams or totems, and an underground section with traps and obstacles such as fans that would have possibly lifted Sonic in the air. Mountains can be seen further behind.


Three normal enemies and one boss are known to belong to the R2 level, according to Whitehead. This includes an antlion enemy, a worm or snake, and a enemy armed with a drill. Concept art depicting Eggman in a wheel mech may indicate plans for the boss.


Unfinished sprites also shared by Whitehead[5] show how these enemies may have appeared in game. This time, Eggman is depicted riding a vehicle with a giant wheel on the bottom and a spring on the back.

With the removal of R2, the Antlion enemy was considered for Metallic Madness (R8) before being scrapped entirely (the sprite was slightly redrawn, with the highlight on it being smaller). It is speculated that parts of Metallic Madness' level design, namely the sloped pits, may have been created with the Antlion enemy in mind, before being repurposed. The leaked prototypes suggest the developers experimented with these sections before deciding on regular, upwards spikes.


Several explanations have been given for R2's removal. Naoto Ohshima has suggested it may have been down to the design being incompatible with Sonic's speed[1], while Masato Nishimura believes the decision was made because the music data did not fit into the CD-ROM of the game[6].

In an interview with Jim Tretheway regarding the PC version of the game, it was stated that the level was likely cut as it didn't meet quality standards[7].

Final game leftovers

Questions of R2 were raised shortly after Sonic CD's release. Performing its level select code, the level order jumps from "1-2-D" (Palmtree Panic 2, bad future) to "3-1-A" (Tidal Tempest 1, present), with the time warp screen, introduction and an unused "comin' soon" screen occupying the level slots in between (1-3-C and 1-3-D, Palmtree Panic 3, not appearing in the list until after Tidal Tempest). With no levels beginning with a "2", it was speculated that the second level no longer existed on the disc. This pattern was later mirrored by the PC version, which in the game's files, has folders for "R1" and "R3", but not "R2".

Perhaps the biggest clue that something is missing from the game is the ending sequence, which shows animated sections of the game, in level order. After a sequence in Palmtree Panic, Sonic is seen what looks like a ruined area with blue or grey metallic structures or pillars, with areas of vegetation growing around. Stone tiles collapse as Sonic touches them, revealing quicksand, and at the end, Sonic is attacked by the unseen Antlion enemy. Nothing resembling this sequence exists in the final game.

(an animated gif of the scene can be found here.)

These animated sequences were created in advance of much of the game, and are therefore thought to be based on older concept art and ideas, including those of R2. This sequence was left in the final game (being re-drawn for the Mega-CD's limited colour palette) and subsequent re-releases, as well as the video included in the Sega Saturn compilation, Sonic Jam.

According to Masato Nishimura, the default song in the D.A. Garden mode, "Little Planet" (composed by Masafumi Ogata), is a leftover from R2[8]. A brief remix of the "Bad Future" theme of the stage is also present in Ogata's song "Techno Power Mix", composed for the 1994 album Sonic the Hedgehog - Remix. "Sonic Stream", another of Ogata's tracks from the same album, is also speculated to feature pieces, or be a full remix of R2's "Good Future" theme.


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