Sonic CD
is a 1993 platform game developed and published by Sega for the Sega CD. As Sonic the Hedgehog, the player attempts to protect an extraterrestrial body, Little Planet, from Doctor Robotnik. Like other Sonic games, Sonic runs through themed levels while collecting rings and defeating robots. Sonic CD introduces time travel as a game mechanic. By traveling through time, players can access different versions of stages, featuring alternative layouts, music, and graphics. Sonic CD features the debuts of the characters Amy Rose and Metal Sonic.
Sonic CD began as a port of the Sega Genesis game Sonic the Hedgehog, but developed into a separate project. Led by Sonic co-creator Naoto Ohshima, the developers sought to showcase the technical capabilities of the Sega CD, with animated cutscenes by Studio Junio and CD-quality music. The soundtrack, influenced by house and techno, was composed by Naofumi Hataya and Masafumi Ogata. For North America, a new soundtrack was composed by Spencer Nilsen, David Young and Sterling Crew.
Sonic CD was released in late 1993. It received acclaim and is often regarded as one of the best Sonic platform games. Reviewers praised its size, music, and time travel feature, although some felt it did not fully use the Sega CD's capabilities. It sold over 1.5 million copies, making it the bestselling Sega CD game. Sonic CD was ported to Windows as part of the Sega PC label in 1996, and to the PlayStation 2 and GameCube as part of Sonic Gems Collection in 2005. A remake, developed by Christian Whitehead using the Retro Engine, was released for various platforms in 2011 and as part of the Sonic Origins compilation in 2022.
Gameplay
Sonic CD is a side-scrolling platform game similar to the original Sonic the Hedgehog. Players control Sonic the Hedgehog as he ventures to stop his nemesis Doctor Robotnik from obtaining the magical Time Stones and conquering Little Planet. Like previous games, Sonic can destroy enemies and objects by rolling into a ball, and collects rings as a form of health. Sonic can also perform a "spin dash" and a "super peel-out", both of which increase his speed. The game has seven levels; each is split into three zones, the third of which ends in a boss fight against Robotnik. Players start with three lives, which are lost when they suffer any type of damage without rings in their possession; losing all lives results in a game over.Sonic CD is differentiated from other Sonic games through its time travel game mechanic, which allows players to access different versions of rounds set in the past, present, and future. The music also changes within the different time zones, as remixes of the present music. Sonic starts the first two zones in the present. The third zone is always set in the future, its timeline dependent upon whether the player destroyed both transporters in the past. He travels through time by hitting signs labelled "past" or "future", maintaining his speed afterward. By default, future stages are neglected and littered with machinery after Robotnik has conquered the Little Planet, appropriately named "bad futures." Players are encouraged to convert each zone into a "good future", with bright colors, thriving nature, and few enemies. To achieve a good future in each zone, players must travel to the past and destroy a hidden transporter where enemy robots spawn. Achieving a good future in every zone unlocks the best ending.
By finishing a level with more than 50 rings, Sonic can access a special stage, in which he must destroy six UFOs in a pseudo-3D environment within a time limit. Time is reduced swiftly if the player runs through water, though a special UFO that appears when time is running out grants extra time if destroyed. If the player destroys all the UFOs before the time runs out, they earn a Time Stone. Collecting all seven Time Stones automatically creates a good future in every zone, unlocking the best ending. The game also features a time attack mode, where players can replay completed levels for the fastest time possible; a "D.A. Garden", where players can listen to the music of completed zones; and a "Visual Mode", where players can view the opening and closing animations. The game also includes a save feature, which uses the back-up memory of the Sega CD.
Plot
At Never Lake, an extraterrestrial body, Little Planet, appears in the last month of every year. Sonic's nemesis, Dr. Robotnik, has chained the planet to a mountain and begun transforming it into a giant fortress with his robot army. To execute his plan, Robotnik uses the Time Stones, seven diamonds which control the flow of time, hidden in the different zones. Sonic ventures to the planet, followed by the besotted Amy Rose, his self-proclaimed girlfriend. Robotnik dispatches his newest invention, Metal Sonic, to kidnap Amy at Collision Chaos, luring Sonic into danger.After outrunning Metal Sonic in Stardust Speedway and saving Amy, Sonic fights and defeats Robotnik in his lair, Metallic Madness. Two endings exist, depending on whether or not the player collected the Time Stones or achieved a good future in each level. In the good ending, Little Planet thanks Sonic with a shower of stars and leaves Never Lake; in the bad ending, Little Planet still leaves, but Robotnik uses the Time Stones to bring it back and the player is urged to replay the game to achieve the good ending.
Development
Background and conception
The original Sonic the Hedgehog was developed by Sonic Team at Sega. It was a major commercial success and positioned Sega as Nintendo's main rival in the console market. The lead programmer, Yuji Naka, dissatisfied with Sega of Japan's rigid corporate policies, moved with several members of Sonic Team to the United States to develop Sonic the Hedgehog 2 with Sega Technical Institute. Meanwhile, Sega planned to release the Sega CD add-on for its Genesis, and wanted a Sonic game that would demonstrate its more advanced features. Naoto Ohshima, the designer of Sonic, was Sonic CDs director; the remainder of the team comprised Sega staff who had developed The Revenge of Shinobi, Golden Axe II, and Streets of Rage. The team built Sonic CD using the original Sonic the Hedgehog code as a base.Sonic CD was conceived as an enhanced port of Sonic the Hedgehog for the Sega CD, but it gradually developed into a separate project. It was titled CD Sonic the Hedgehog before being renamed Sonic CD. Ohshima does not consider Sonic CD a sequel to Sonic the Hedgehog or Sonic 2, although the artist Yasushi Yamaguchi said its story may be set between the two.
Design
Sonic the Hedgehog had a balance on speed and platforming; STI built on the speed with Sonic 2s more focused level designs. However, Ohshima's team sought to focus on the platforming and exploration aspects. Ohshima said, "our ideas were to make the world and setting larger, and to add more replayability, so it would be something you could enjoy playing for a long time". According to artist Kazuyuki Hoshino, because it was a Sega CD game, the team wanted Sonic CD to stand out compared to previous Sonic games. The visuals were designed to resemble CG imagery; the Sonic sprite on the title screen was based on a Sonic figurine by Taku Makino that the team photographed and scanned.Sonic CD marks the debuts of Amy Rose and Metal Sonic, both designed by Hoshino. Although Hoshino created Amy's in-game graphics, many staff members contributed ideas to her design. Her headband and trainer shoes reflected Ohshima's tastes while her mannerisms reflected the traits Hoshino looked for in women at the time. Hoshino designed Metal Sonic in response to Ohshima wanting a strong rival for Sonic. Hoshino had a clear image of Metal Sonic in his mind from the moment he was briefed, and his design emerged after only a few sketches. The character graphics were created using Sega's proprietary graphics system for the Genesis, the "Sega Digitizer MK-III", featuring a bitmap and animation editor. The team mostly used Macintosh IIcis. Graphics data was stored on 3.5-inch floppy disks, which were handed to the programmer to work into the game. Though Naka was not directly involved with Sonic CD, he exchanged design ideas with Ohshima.
Ohshima cited the film Back to the Future as an influence on the time travel. The developers designed four variants of each stage, one for each time period. Ohshima hoped for the period to change instantly with a "sonic boom" effect, but the programmers argued this was impossible and produced a loading sequence instead. Sega did not pressure the team developing Sonic CD as much as the one developing Sonic 2. Ohshima felt this was because Sonic CD is not a numbered sequel; he considered it a recreation of the original game. The total Sonic CD game data is 21 megabytes, compared to Sonic 2s 1 MB. Sonic CD includes animated cutscenes animated by Studio Junio and produced by Toei Animation. The videos used the STM format, which provided uncompressed imagery to the video display processor, creating better results than the Cinepak compression used for other Sega CD games. The special stages feature Mode 7-like background plane manipulation effects. An underground dungeon stage was cut early in development as it did not fit the Sonic gameplay.
Music
The Sonic CD soundtrack was composed by Naofumi Hataya and Masafumi Ogata. According to Hataya, Sega allocated a large audio budget to showcase the audio functionality of the Sega CD, aiming for CD-quality music superior to video game music of the time. The team worked with the Japanese music production company Being, and enlisted Keiko Utoku to provide vocals. The music was recorded in the Being studios.Hataya and Ogata's first demos were rejected by Ohshima, who wanted a more bold, experimental sound. They instead composed music inspired by the increasing popularity of house and techno in Japan, citing inspiration from acts including C+C Music Factory, Frankie Knuckles and the KLF. They were also inspired by the popularity of Sonic in British DJ culture at the time. The team composed music to match the past, present and future versions of each stage. While most tracks use CD audio, the past stages use sample-based PCM tracks to evoke a "prehistoric" feeling. An album of remixes by Hataya and Ogata was released in Japan in late 1994.
Sega of America delayed the North American release of Sonic CD by two months to have a new soundtrack composed by Spencer Nilsen and David Young, with the addition of the boss music and the themes for the Collision Chaos and Metallic Madness stages by Sterling Crew. Nilsen said Sega of America "wanted something a little more musically rich and complex", with a theme song they could use in marketing. The new theme song, "Sonic Boom", was composed by Nilsen and performed by the female vocal trio Pastiche. Den of Geek described the American soundtrack as "more orchestral and 'rocking'... a bit more 'epic' and almost mournful", with "a sense of dread" compared to the "bouncy and joyful" Japanese soundtrack. Nilsen said the two soundtracks represented "completely different musical philosophies and approaches".