Sonic the Hedgehog CD is a 1993 platform game made and sold by Sega for the Sega CD. Players control Sonic to protect Little Planet, an alien planet, from Doctor Robotnik. Just like other Sonic games, players run through themed levels, collect rings, and defeat robots. Sonic CD adds time travel as a feature. Players can visit different versions of levels with new designs, music, and pictures. Sonic CD introduces the characters Amy Rose and Metal Sonic for the first time.
The game started as a version of the 1991 Sega Genesis game Sonic the Hedgehog but became its own project. Naoto Ohshima, who helped create Sonic, led the team. They wanted to show the Sega CD's powerful features, including animated scenes made by Studio Junio and Toei Animation, and high-quality music. The music, inspired by house and techno, was made by Naofumi Hataya and Masafumi Ogata. For North America, Spencer Nilsen, David Young, and Sterling Crew created a new soundtrack.
Sonic CD was released in late 1993. It was well-received and is often considered one of the best Sonic platform games. Reviewers liked its large size, music, and time travel feature. However, some said it didn't use the Sega CD's full power. It sold more than 1.5 million copies, becoming the top-selling Sega CD game. The game was later released on Windows as part of the Sega PC label in 1996. It also appeared on PlayStation 2 and GameCube in 2005 as part of Sonic Gems Collection. A remastered version, made by Christian Whitehead using the Retro Engine, was released on multiple platforms in 2011. It was also included in the Sonic Origins collection 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 tries to stop his enemy, Doctor Robotnik, from getting magical Time Stones and taking over Little Planet. Like other Sonic games, Sonic can defeat enemies and break objects, such as walls and screens with power-ups, by rolling into a ball. He collects rings to stay healthy. Sonic can also use a "spin dash" and a "super peel-out" to move faster. The game has seven levels, each divided into three zones. The third zone ends with a boss fight against Robotnik. Players begin with three lives, which are lost if they take damage without any rings. Losing all lives ends the game.
Sonic CD is different from other Sonic games because it includes a time travel feature. Players can visit different versions of levels set in the past, present, and future. The music changes in each time zone, with rearranged versions of the present music. Sonic starts the first two zones in the present. The third zone is always in the future, and its timeline depends on whether the player destroyed both transporters in the past. Sonic moves through time by hitting signs labeled "past" or "future," keeping his speed after touching them. Future stages are usually ruined and filled with broken machines, called "bad futures." Players aim to change each zone into a "good future," which has bright colors, healthy nature, and few enemies. To do this, players must go to the past and destroy a hidden transporter where enemy robots appear. Completing this in all zones unlocks the best ending.
If players finish a level with more than 50 rings, they can enter a special stage. In this stage, Sonic must destroy six UFOs in a 3D-like environment within a time limit. Time decreases quickly if the player runs through water. However, a special UFO appears when time is low and gives extra time if destroyed. If all UFOs are destroyed before time runs out, the player earns a Time Stone. Collecting all seven Time Stones automatically creates a good future in every zone, unlocking the best ending. The game also includes a time attack mode, where players can replay levels to beat their fastest time. A "D.A. Garden" lets players listen to music from completed zones, and a "Visual Mode" shows the opening and closing animations. The game includes a save feature that uses the backup memory of the Sega CD.
Plot
At Never Lake, an alien object called Little Planet appears every December. Sonic's enemy, Dr. Robotnik, has attached the planet to a mountain and is using his robot army to turn it into a large fortress. To complete his plan, Robotnik uses the Time Stones, seven diamonds that control time, which are hidden in different areas. Sonic travels to the planet, with Amy Rose, who is very fond of Sonic, following him. Robotnik sends his latest creation, Metal Sonic, to capture Amy at Collision Chaos, tricking Sonic into a dangerous situation.
After fighting and escaping Metal Sonic at Stardust Speedway and rescuing Amy, Sonic confronts and defeats Robotnik in his base, Metallic Madness. Two endings occur based on whether the player collected all the Time Stones or performed well in each level. In the good ending, Little Planet thanks Sonic with a shower of stars and departs Never Lake. In the bad ending, Little Planet leaves, but Robotnik uses the Time Stones to return it, and the game encourages the player to replay to achieve the good ending.
Development
The first Sonic the Hedgehog game was created by Sonic Team at Sega in 1991. It became very popular and helped Sega become a major competitor to Nintendo in the video game console market. Yuji Naka, the lead programmer, was unhappy with Sega Japan’s strict rules, so he moved to the United States with some members of Sonic Team to work on Sonic the Hedgehog 2 with Sega Technical Institute (STI). At the same time, Sega planned to release the Sega CD add-on for its Genesis console and wanted a Sonic game that would show off the CD’s advanced features. Naoto Ohshima, the designer of Sonic, directed Sonic CD. The rest of the team included staff who had worked on games like The Revenge of Shinobi, Golden Axe II, and Streets of Rage. They used the original Sonic the Hedgehog code as a starting point for Sonic CD.
Sonic CD was originally planned as an improved version of Sonic the Hedgehog for the Sega CD, but it became its own separate project. It was first called CD Sonic the Hedgehog before being renamed Sonic CD. Ohshima does not consider Sonic CD a direct follow-up to Sonic the Hedgehog or Sonic 2, even though artist Yasushi Yamaguchi suggested its story might take place between those two games.
Sonic the Hedgehog balanced speed and platforming, and STI made Sonic 2 faster with more focused level designs. Ohshima’s team, however, wanted to focus more on exploration and platforming. Ohshima said the team aimed to create a larger world and add more replayability so players could enjoy the game for a long time. Artist Kazuyuki Hoshino said the team wanted Sonic CD to stand out from previous Sonic games because it was a Sega CD game. The visuals were designed to look like computer-generated imagery. The Sonic sprite on the title screen was based on a figurine by Taku Makino that the team photographed and scanned.
Sonic CD introduced two new characters: Amy Rose and Metal Sonic, both designed by Hoshino. While Hoshino created Amy’s in-game graphics, other team members contributed ideas to her design. Her headband and shoes reflected Ohshima’s preferences, while her behavior showed traits Hoshino observed in women at the time. Hoshino designed Metal Sonic to be a strong rival for Sonic. He had a clear vision for Metal Sonic from the start and created the design after only a few sketches. The team used Sega’s proprietary graphics system, the "Sega Digitizer MK-III," and mostly worked on Macintosh IIcis computers. Graphics data was stored on 3.5-inch floppy disks and given to the programmer to include in the game. Though Yuji Naka was not directly involved with Sonic CD, he shared design ideas with Ohshima.
Ohshima said the movie Back to the Future (1985) influenced the time-travel concept. The developers created four versions of each stage, one for each time period. Ohshima wanted the time changes to happen instantly with a "sonic boom" effect, but programmers said it was impossible and used a loading screen instead. Sega gave the Sonic CD team more freedom than the team working on Sonic 2. Ohshima believed this was because Sonic CD was not a numbered sequel but a recreation of the original game. The total Sonic CD game data is 21 megabytes (MB), compared to Sonic 2’s 1 MB. Sonic CD includes animated cutscenes made by Studio Junio and produced by Toei Animation. The videos used the STM format, which provided high-quality, uncompressed imagery better than the Cinepak compression used in other Sega CD games. The special stages used effects similar to Mode 7 background plane manipulation. An underground dungeon stage was removed early in development because it did not fit Sonic’s gameplay style.
The Sonic CD soundtrack was composed by Naofumi Hataya and Masafumi Ogata. Sega allocated a large budget to highlight the Sega CD’s audio capabilities, aiming for music quality better than other video games of the time. The team worked with the Japanese music company Being and hired Keiko Utoku to provide vocals. The music was recorded in Being’s studios.
Hataya and Ogata’s first demos were rejected by Ohshima, who wanted a bolder, more experimental sound. Instead, they composed music inspired by the growing popularity of house and techno in Japan, drawing from artists like C+C Music Factory, Frankie Knuckles, and the KLF. They were also influenced by Sonic’s popularity in British DJ culture. The team created music that matched the past, present, and future versions of each stage. Most tracks used CD audio, but the past stages used sample-based PCM tracks to create a "prehistoric" feel. 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 add a new soundtrack composed by Spencer Nilsen and David Young. This included music for the boss battles and themes for the Collision Chaos and Metallic Madness stages by Sterling Crew (credited only as "Sterling"). Nilsen said Sega of America wanted music that was "more musically rich and complex" and a theme song for 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," contrasting with the "bouncy and joyful" Japanese soundtrack. Nilsen said the two soundtracks represented "completely different musical philosophies and approaches."
Release
Sonic CD was released in Japan on September 23, 1993, and in Europe a few weeks later in October. It was delayed because of the new soundtrack and later released in North America on November 23, 1993. This release included Sonic CD, Sonic Chaos, and Sonic Spinball as part of Sega of America's "Sonic Three on One Day" plan. Sonic CD was the main game for Sega CD and the only Sonic game on that system. An improved version of the original Sonic the Hedgehog and a version of Popful Mail with Sonic themes were canceled.
Rereleases
Two versions of Sonic CD were released for Windows: one in 1995 for Pentium processors and another in 1996 for DirectX. The Pentium version was only included with new computers and was never sold in stores. Sega worked with Intel to ensure the game functioned correctly. The DirectX version was released under the Sega PC label. It was available in North America on July 8 and in Japan on August 9. This version is mostly the same as the original release, but it includes loading screens and is only compatible with older Windows versions. Both Windows versions use the North American soundtrack.
The 1996 Windows version was later adapted for the GameCube and PlayStation 2 in August 2005 as part of Sonic Gems Collection. This version uses the original Japanese soundtrack in Japan and the North American soundtrack elsewhere. Some graphical issues, such as a blurry anti-flicker effect, were introduced in these ports. However, the opening animation is displayed in a higher quality fullscreen view.
In 2009, an independent developer named Christian Whitehead created a proof-of-concept video for a remastered version of Sonic CD using his Retro Engine on iOS. Sega released this version in December 2011 for Android, iOS, PlayStation 3, and Xbox 360, and in January 2012 on Steam. BlitWorks helped with the PC and console versions. The remaster includes improvements such as widescreen graphics, better collision detection for time travel, refined visuals and frame rates for Special Stages, the option to use spin dash physics from Sonic the Hedgehog 2, both the Japanese and North American soundtracks, the ability to unlock Tails as a playable character, and support for achievements and trophies. Whitehead designed two new stages, but they were not included because Sega wanted to keep the game true to its original release. The remaster was not released on the Wii due to download size limits. It was later included in the 2022 compilation Sonic Origins, which removed voice lines for Sonic and Amy. Later, Amy and Knuckles became playable characters in an update to Origins.
Reception
The Sega CD version sold over 1.5 million copies, becoming the system's top-selling game. In the United Kingdom, it was the best-selling Mega-CD game in December 1993.
Sonic CD received positive reviews. Critics praised its presentation, visuals, and audio. Computer and Video Games noted that while the game did not fully use the Sega CD's features, its graphics and sound were high quality, with music from groups like 2Unlimited and Bizarre Inc. Electronic Games said the game looked similar to older titles and used the Sega CD's special features only slightly, but this did not reduce its quality. The music was highlighted as a key strength, helping the game "stand above the crowd." Electronic Gaming Monthly (EGM) praised the animated scenes and sound but mentioned frame rate issues during special stages. Later reviews also praised the game's visuals, with IGN noting its vibrant colors and GamesRadar saying its music remained fresh over time.
Opinions about the North American soundtrack were mixed. GameFan, which had given the Japanese version a perfect score, criticized the change. In 2009, GameFan editor Dave Halverson called it "an atrocity" and one of the worst localization decisions. A GamesRadar reviewer said he turned off his GameCube in frustration after discovering the American soundtrack in Sonic Gems Collection. However, others argued the criticism was exaggerated, comparing it to replacing music in a movie long after its release.
The gameplay was widely appreciated. EGM praised the variety of levels and the time-travel mechanic, which added depth. Electronic Games said the game played as well as earlier Sonic titles, with time-travel and special stages increasing replayability. Sega Pro noted the expanded environments and replay value but felt the game was too easy. Sega Magazine called it "potentially a classic," and GameSpot highlighted the "interesting level design" and time-travel gameplay as major strengths.
Critics called Sonic CD one of the best Sega CD games. Electronic Games called it a must-have, and Sega Pro described it as "brilliant" and worth its price. Destructoid called it "a hallmark of excellence," creative, and exciting, saying to miss it would be to miss one of the franchise's best titles.
Reception to later versions of Sonic CD varied. GameSpot criticized the 1996 Windows version for poor technical performance and "tedious" gameplay, saying it offered little new for those who had played on Sega systems. Reviews of the version in Sonic Gems Collection were more positive, with IGN calling it a standout for the compilation and Eurogamer calling it "rejoice-worthy" but noting the rest of the collection was weak. The 2011 console version received "generally favorable reviews," while the iOS version got "universal acclaim." Sonic CD is often listed among the best Sonic and platform games. In 1997, EGM ranked it the 17th best console game of all time, citing its bonus levels and animated intro.
Legacy
The story of Sonic CD was adapted in the 25th issue of Archie Comics' Sonic the Hedgehog comic book series. This version included changes, such as Tails playing a key role and Metal Sonic being able to speak. British publisher Fleetway Publications also created their own version in Sonic the Comic. The final issue of Archie's comic, #290 (December 2016), included a retelling of the game's story.
Two characters from Sonic CD, Amy Rose and Metal Sonic, became regular parts of the Sonic series. Metal Sonic appeared as a villain in Knuckles' Chaotix (1995), the Sonic the Hedgehog anime film (1996), Sonic Heroes (2003), Sonic the Hedgehog 4: Episode II (2012), and Sonic Mania (2017). Amy Rose is most famous for her role in Sonic Adventure. The animated scenes from Sonic CD were included as bonus content in Sonic Jam (1997) and Sonic Mega Collection (2002). The song "Sonic Boom" was used as one of Sonic's themes in Super Smash Bros. Brawl (2008).
In 2011, Sega released Sonic Generations to celebrate the franchise's 20th anniversary. This game included a remake of the battle against Metal Sonic. Sonic Mania, made for the series' 25th anniversary, included updated versions of Sonic CD's Stardust Speedway and Metallic Madness levels, along with a battle against Metal Sonic.
The 2027 film Sonic the Hedgehog 4 was thought to be based on Sonic CD's main story after a mid-credits scene in Sonic the Hedgehog 3 (2024) introduced Amy and Metal Sonic at the same time. Jeff Fowler, the director of the Sonic film series, said he believed it "felt very cool to honor that chronology and have them introduced simultaneously."