Master System / Game Gear1993AspectPlatformer

Sonic Chaos (1993)

South Island is sinking, Dr. Eggman has the red Chaos Emerald, and for the first time on an 8-bit Sega you can play as Tails. Strap on the Rocket Shoes: this one is built for speed.

Released19 Nov 1993 (JP) · 23 Nov 1993 (US, UK)

DeveloperAspect, for Sega

Japanese titleSonic & Tails

ZonesSix, three acts each

Players1

PlayableSonic or Tails

Overview

Sonic Chaos is the third of Sega’s 8-bit Sonic platformers, built by Aspect (the studio behind the 8-bit Sonic the Hedgehog 2) and released on the Master System and Game Gear at the end of 1993. In Japan it went out on the Game Gear as Sonic & Tails, a title that tells you exactly what was new.

After the 8-bit Sonic 2, where Tails only turned up in cutscenes, the fox finally gets the controls, flight and all. Sonic picks up tricks that Mega Drive owners already loved, the Spin Dash and a dash-from-standing move the manual calls the Strike Dash (the Super Peel-Out), and for the first time on 8-bit the Chaos Emeralds are won in Special Stages.

Aspect also turned the difficulty right down. After the notoriously tough 8-bit Sonic 2, the acts here are short, fast and built for flat-out running, the boss acts finally hand out rings, and Rocket Shoes can carry you through half a level in seconds. Critics in 1993 mostly loved the looks and the speed; a few grumbled that it was far too easy.

Quick Answers

The quick version, with the detail further down the page.

Plot / Story

South Island runs on borrowed power. Every version of the Sonic Chaos manual agrees on the basics: the six Chaos Emeralds keep the island in one piece, Dr. Robotnik (Dr. Eggman in Japan) wants them, and the moment he pulls a single gem out of the set, the whole arrangement comes apart.

How it comes apart depends on which box you bought. The European booklet plays it as a cartoon, with an explosion, a raid on the cave where the gems were kept and Flicky the bluebird raising the alarm. Sega of America’s version is blunter: the other five lose their balance and drop into a parallel universe, while Robotnik eyes them as raw material for weapons. In the Japanese Sonic & Tails booklet the heroes are away on an adventure, hear a rumour and race home to find the island already going under.

Whichever you read, the job is the same. Sonic and Tails have to cross a sinking island, find the missing gems before it slips into the sea and prise the red one out of the doctor’s grip. The American manual even lets Sonic close with a joke, booking the doctor for contempt of hedgehog.

Five Emeralds and a showdown

In the game itself the hunt is split in two. Five of the gems wait in Special Stages, and the door to those is a 100-ring haul inside a single act; only Sonic can step through it. The sixth, the red one, never leaves Eggman until his last machine falls.

So the ending you get is decided long before Electric Egg. Arrive with five Emeralds and beating the Laser Walker wins back the sixth and saves the island. Arrive short, or play as Tails, who has no Special Stages at all, and the doctor flies off with his prize.

Zones in Sonic Chaos

Six zones, all on South Island. Acts 1 and 2 are full levels; Act 3 is a short run to the boss, and from this game on it comes with rings. Finish Act 1 or 2 and a Bonus Panel spins for a prize, with your speed shown above it in kilometres per hour.

1. 
   Turquoise Hill ZoneActs 1–3 · boss: Lady BugA sunny opener that borrows its corkscrews from Sonic 2’s Emerald Hill. Mind the Boing-o-Bots: the springs on their backs send you flying, so Spin Dash into them instead.
2. 
   Gigalopolis ZoneActs 1–3 · boss: Bead WormNight falls on a city still under construction. Its slanted bridges only hold you at full tilt. The two versions play different music here: the Master System track covers “Oh Yes!”, a Korg M1 synthesizer demo, and Western Game Gear title cards call the place Gigapolis.
3. 
   Sleeping Egg ZoneActs 1–3 · boss: Bouncy Boss RobotEggman’s building site in the sky, with his face on the walls. The real enemy is gravity: there are gaps everywhere, and the Pogo Springs are your way up.
4. 
   Mecha Green Hill ZoneActs 1–3 · boss: Tree CrawlerThe Japanese manual calls it Green Hill, mechanised, and it looks the part: metal palms lob coconut bombs and oil fills the low ground. The tune reworks Green Hills from the 8-bit Sonic 2.
5. 
   Aqua Planet ZoneActs 1–3 · boss: Sphere-o-BotShallow water, deep trouble. Push a door and the current drags you through the tunnel behind it, and air bubbles are rare. Roll fast enough and you skip across the top like a stone.
6. 
   Electric Egg ZoneActs 1–3 · boss: Laser WalkerThe last stop is a computer fortress. Lasers ride rails and fire when you pass beneath them, mine carts end at pits, and Act 3 brings back Scrambled Egg’s music from Sonic 2.

The Special Stages sit outside the zones. There are five of them, each with one Emerald and a time limit.

In comics, TV & other media

Sonic Chaos arrived just as Fleetway’s Sonic the Comic was finding its feet, and British readers got the game from every angle. More in Sonic in other movies and media.

Characters

A small cast with one big change: Sonic finally shares top billing. Here is who is who, and what each of them brings to South Island.

Character	Who they are	In this game	Stats & abilities
Sonic the HedgehogPlayable hero	Sega’s blue mascot, designed by Naoto Ohshima for the 1991 Mega Drive game. Here he is in his third 8-bit platformer. The Japanese manual pitches him with total swagger and gives him the one job nobody else can do: collecting every Chaos Emerald.	The Emerald hunter. Only Sonic can enter the Special Stages, so only Sonic can win the five Emeralds there and claim the sixth from Eggman for the good ending.	Spin Dash: hold Down and tap a button, then let go Strike Dash (the Super Peel-Out): faster, but he is upright and can be hit Rocket Shoes: a burst of speed and short flight Pogo Spring: huge bounces Starts with 3 lives, no continues
Miles “Tails” ProwerPlayable for the first time on 8-bit	A young two-tailed fox who first appeared in 1992 in the 8-bit and Mega Drive versions of Sonic the Hedgehog 2. His Japanese profile is written in his own voice and it is pure hero worship: one day he wants to be Sonic, and he admits there is plenty of training to do first.	The easy-going option. Tails runs the same zones but skips the Emerald hunt entirely, so his game always ends with Eggman keeping the red Emerald. Sonic Chaos was the first game anywhere to let the player control his flight.	Flight: takes off from a standstill and hovers if you let go of the pad, for a short while Spin Dash Slower top speed than Sonic Starts with 5 lives and 3 continues Gets 10-ring boxes where Sonic finds Rocket Shoes
Dr. EggmanDr. Ivo Robotnik in the West	Sega’s moustached mad scientist and Sonic’s nemesis since 1991. The Japanese manual makes a running joke of his stubbornness: beaten twice already, he is back for round three, still crazy about Chaos Emeralds and still plotting to rule the world.	Steals the red Chaos Emerald and sets the whole disaster off. He meets the heroes at the end of every zone in a new machine, from a giant spring-backed ladybird to a walking laser tank in Electric Egg.	Six bosses, one per zone Final machine: the Laser Walker, 16 hits plus one Holds the sixth Emerald to the end
FlickyThe bluebird who raises the alarm	One of South Island’s animals, a little blue bird who has been part of Sonic’s world since the first game. (The picture is later Sega artwork.)	In the European manual it is Flicky who discovers that the Emeralds are gone from the North Cave. In the game, her face on the Bonus Panel means no prize.	Not playable.

Badniks and bosses

Aspect gave Chaos its own robot zoo. Names are the Western manual’s, with the Japanese ones in brackets; the pictures are Sega’s artwork from our original gallery, and screenshots for the last two bosses.

• Boing-o-BotTurquoise Hill · Mecha Green HillA Moto Bug with a spring on its back (Bane Motora). Hit it from the side.
• BeetonTurquoise Hill · Gigalopolis · Electric EggA robot bee that, unlike Buzz Bomber, never fires.
• Metal-o-TurtleGigalopolisCalled a turtle, looks like a stag beetle (Dokabuton).
• FroggerSleeping EggA frog’s head on a pogo-stick jackhammer.
• Veg-o-BotSleeping EggA hopping, onion-shaped mystery machine (Tsuno-tsuno).
• Mecha Hiyoko & BomblinAqua Planet · Electric EggHopping chick-bots in threes, and a waddling mine that bursts into sparks.
• Lady BugBoss · Turquoise HillA giant gold Boing-o-Bot (Great Bane Motora Gold). Spin Dash into it.
• Bead WormBoss · GigalopolisA swaying tower of balls (Dangerous Ball Tower) that throws its own segments.
• Bouncy Boss RobotBoss · Sleeping EggA pogoing, gun-toting Eggman lookalike (Hopping Egg Vulcan). Only the head is weak.
• Tree CrawlerBoss · Mecha Green HillShins up a robot palm and spits fire (Kamado MAX).
• Sphere-o-BotBoss · Aqua PlanetSends Mecha Hiyokos first, then bounces in itself, guns blazing.
• Laser WalkerFinal boss · Electric EggEggman in a small two-legged walker (Killer Turkey Gou).

The people who made it

Aspect credited its team by nickname, as it did on all its Sonic games. The Western Game Gear manual adds the Sega of America side.

How it was made

Chaos was Aspect’s second Sonic game and its chance to fix what people said about the first. Our original page had no history section, so this one is new, pieced together from Sonic Retro’s prototype research, Wikipedia’s account of the production, the game’s hidden data and the build dates logged by Hidden Palace.

Catching up with the Mega Drive

Play the 8-bit Sonic 2 and then Chaos, and the jump is obvious: the new game raids the Mega Drive for ideas. Tails is playable at last, both heroes get the Spin Dash, Sonic picks up a version of Sonic CD’s Peel-Out (here the Strike Dash), and Turquoise Hill copies the corkscrews from Emerald Hill. Even the title tune and the death jingle are carried over from Aspect’s own Sonic 2, in a higher key.

Closing that gap was the job. Chaos was built largely on the Master System Sonic 2, and Aspect used what it had learned there to make a bigger, faster and better-looking game; Sonic Retro adds that the earlier game, made separately from the Mega Drive Sonic 2, leaned more on the first Sonic. For most of development the new game was called Sonic the Hedgehog 3. The name changed late, possibly so that it would not be confused with the Mega Drive Sonic 3, still unannounced at the time and a very different game.

One game, two screens

Put the two finished versions side by side and the Game Gear one has its own fonts, title screen, menus and title cards, some different music and reworked third acts. Japan’s Sonic & Tails goes further and mixes the two sets of Act 3 layouts.

The prototypes explain why. The Master System was the lead machine, and for much of the project the Game Gear build ran on Master System art that did not fit its smaller screen. The handheld’s own touches, such as new colours for Turquoise Hill and Mecha Green Hill and a fresh Gigalopolis tune, arrived only after the home version was more or less done.

Prototypes and a different box

Several early builds survive: a Game Gear version dated 17 May 1993, Master System builds from 30 June and 13 July, and a Japanese demonstration cartridge, the Jitsuenyou Sample. The finished Master System cartridge carries the build date 3 August 1993.

Early screenshots show a darker Turquoise Hill with a different status bar (that dark grass even made it into the Master System manuals), a longer Bead Worm, a green-skied Mecha Green Hill, an Aqua Planet without water and a Special Stage that Tails could enter. Magazines also printed a North American box that never shipped: on it Sonic and Tails run hand in hand, where the finished cover puts Sonic on a Pogo Spring.

Firsts: what this game introduced

Chaos brought a pile of Mega Drive ideas to the 8-bit series, and added a couple of its own.

Cheats & secrets

Our original Sonic Chaos page had no cheats section, so these are new. Each was checked against Sonic Retro’s hidden-content notes.

Zone select

On the title screen press Up, Up, Down, Down, Right, Left, Right, Left, then 1 or 2 on the Master System, or Start on the Game Gear. You will hear the extra-life jingle. On the Game Gear Micro the code is just Up, Up, Down, Down.

Sound test

On the title screen press Down, Down, Up, Up, Left, Right, Left, Right, then 1 or 2 (Master System) or Start (Game Gear). Game Gear Micro: Down, Down, Up, Up. Both codes are riffs on Konami’s famous cheat.

Hadouken

With the sound test code entered, press Down, Down-Right, Right and then 1 or 2 in a level: Sonic throws a fireball, Street Fighter style.

Free Chaos Emerald (Game Gear)

On the character select screen press Up, Down, Up, Down, 1, 2, 1, 2, 1, 2 to start the adventure with one Emerald already collected.

The Kattobi Saisoku Technique contest (Japan)

In December 1993 three Japanese children’s magazines, Shogaku Sannensei, Yonensei and Rokunensei, ran a speed contest on Turquoise Hill. Finish Act 1 or 2 faster than 700 km/h, pause while the speed is on screen and hold a button combination, and the game shows a six-digit code to post in. Only Sonic & Tails has the feature; it was removed from Sonic Chaos.

Codes checked against Sonic Retro, November 2026.

Glitches, exploits and oddities

Chaos is a tidy little game, but a few quirks slipped through, and some never got fixed in any release.

The wrong-coloured Emerald

A Game Gear-only slip. Win the last Emerald and the results tally draws it with the wrong palette. The Master System original, built first, gets the colour right.

Loops in reverse

The first loop of Turquoise Hill Act 1 is the place to see it. Strike Dash up the slope behind it, then reverse into the loop at speed: Sonic still makes it round, but his sprite rotates the wrong way, because each loop is only built for one direction of travel.

Stuck in the ceiling

Low ceilings have sticky corners. Jump while running flat out on precisely the right frame and you lodge inside the wall. What happens next is a lottery: another jump may pop you free, send you wandering off-screen with scrambled graphics, or cost you a life.

Oddities

Tucked away in the sound test is a short jingle, 08EH, that neither version ever plays, and the Game Gear adds tune 09BH, which also goes unheard; Aspect recycled it a year later, a little lower, as Sunset Park Act 3 in Triple Trouble. A sprite of Tails running sits in memory during the opening, though he only ever walks on. And the Western Game Gear version trims Gigalopolis to Gigapolis on its title card.

Videos & media

Sega’s own trailer for the collection that brought Chaos back in 2023, and a complete run of the Master System game with every Emerald.

SEGA’s announce trailer for Sonic Origins Plus (2023), which added twelve Game Gear games, Sonic Chaos among them. From the official Sonic the Hedgehog channel.

A complete Master System playthrough with all six Emeralds, from the World of Longplays archive.

Trivia & facts

• In Japan the game is Sonic & Tails, and the sequel is Sonic & Tails 2. The West called them Sonic Chaos and Triple Trouble.

• 

  Gigalopolis has two different soundtracks. The Master System tune is a cover of “Oh Yes!”, a demo song from the Korg M1 synthesiser; the Game Gear got an original piece instead.
• Mecha Green Hill’s music remixes the Green Hills theme from the 8-bit Sonic 2, the same melody that became “Sonic – You Can Do Anything” in Sonic CD.
• Electric Egg Act 3 plays a remix of the 8-bit Sonic 2’s Scrambled Egg theme, which is also the Master System version’s intro music.
• The title music and the losing-a-life jingle are lifted from the 8-bit Sonic 2, played in a higher key.
• The Japanese manual says Mecha Green Hill is simply Green Hill after Eggman has mechanised it.
• Like Aspect’s other Sonic games, the cartridge hides a build stamp at address $C0: the Master System game is “Ver1.20”, dated 3 August 1993.
• Electronic Gaming Monthly named Sonic Chaos the best Sega Game Gear game of 1993.

Media & artwork

Box art, artwork and screenshots, mostly from Sonic Scene’s own galleries. Select any image to view it larger.

• Box art from Sonic Chaos (Game Gear & Master System)
• Screenshots from Sonic Chaos
• Official artwork from Sonic Chaos

Legacy

Chaos set the template for Aspect’s next Sonic game: two playable characters, Special Stages and plenty of Mega Drive moves. Its working title even survived in a way, as Triple Trouble was called Sonic Chaos 2 for part of its development.

Releases and re-releases

• Game Gear (Japan) 19 November 1993 – Released as Sonic & Tails.
• Master System and Game Gear (West) 23 November 1993 – North America (Game Gear) and the UK (both). Some sources date the European Master System cartridge to 25 October.
• Majesco re-release 2001 – A budget Game Gear cartridge in the US (US$14.97).
• Sonic Adventure DX: Director’s Cut 2003–2004 – Game Gear version, GameCube and PC.
• Sonic Mega Collection Plus 2004–2005 – PlayStation 2, Xbox and PC.
• Wii Virtual Console February–March 2009 – The Master System version, emulated by M2.
• Game Gear Micro (blue) 2020 – Built into Sega’s tiny Game Gear revival.
• Sonic Origins Plus 23 June 2023 – One of twelve Game Gear games in the expanded collection.

Where to play it today

Sonic Origins Plus (2023) has the Game Gear version on PlayStation, Xbox, Nintendo Switch and PC, and the blue Game Gear Micro has it built in. Check what is still on sale on your platform.

Sales & reviews

Sales

Sega Retro has no sales figures for either version, and we have not found a reliable one, so we do not give one here. What the record does show is a very warm reception in Europe, where the Master System was still selling well.

• 80%Sega Retro average, Master System (21 reviews)
• 78%Sega Retro average, Game Gear (20 reviews)
• 94%Sega Power, Game Gear
• 8.25/10Electronic Gaming Monthly

Reception and review scores

Period reviews from Sega Retro’s index of magazine scans; scores that were not out of 100 are shown as Sega Retro converts them.

The magazines agreed on the looks and the speed and split over the challenge. Sega Power rated both versions in the 90s, while Mean Machines Sega marked it down for being unoriginal and far too easy. Japanese reviewers were cooler, with Famitsu and Beep! MegaDrive at 70% and 65%.

Honours

Reader reviews

No reader reviews yet. Played it? Give it a score out of 10 and tell other fans what you think.

Write the first review All reader reviews →

Further reading

More from Sonic Scene on Sonic Chaos and the 8-bit games around it:

Sources

Every fact on this page was checked against the sources below (Sonic Retro pages were read through Wayback Machine copies from December 2024 to February 2025, because the live site shows a bot check; each link opens the nearest archived copy). Magazine scores come from Sega Retro’s review index, which links each score to a scan of the original page.

• Overview: Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sonic Retro, Sonic Chaos/Manuals (US, European and Japanese manual stories and profiles); Sega Retro, Sonic Chaos (release dates, prices, product codes, review index with scans); Sonic Wiki Zone, Sonic Chaos (referenced claims only: Japanese booklet story and profiles, EGM award); Sonic Scene, “Sonic Chaos” (original infobox article, Joomla 444)
• Quick Answers: Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sonic Retro, Sonic Chaos/Hidden content (codes, unused content, build dates); Sega Retro, Sonic Chaos (release dates, prices, product codes, review index with scans); SEGA, “Sonic Origins Plus – Announce Trailer” (23 March 2023): twelve Game Gear titles, release 23 June 2023
• Plot / Story: Sonic Retro, Sonic Chaos/Manuals (US, European and Japanese manual stories and profiles); Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sonic Retro zone pages: Turquoise Hill Zone, Gigalopolis Zone, Sleeping Egg Zone, Mecha Green Hill Zone, Aqua Planet Zone, Electric Egg Zone; Sonic Wiki Zone, Sonic Chaos (referenced claims only: Japanese booklet story and profiles, EGM award)
• In comics, TV & other media: Sonic Wiki Zone, Sonic the Comic Issue 12 (Review Zone contents); Sonic Wiki Zone, Sonic the Poster Mag Issue 2; Sega Retro, Sonic Chaos/Reception; Sonic Retro Badnik and boss pages: Boing-o-Bot, Beeton, Metal-o-Turtle, Frogger, Veg-o-Bot, Lady Bug, Bead Worm, Bouncy Boss Robot, Tree Crawler, Sphere-o-Bot, Laser Walker
• Characters: Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sonic Retro, Sonic Chaos/Manuals (US, European and Japanese manual stories and profiles); Sonic Retro Badnik and boss pages: Boing-o-Bot, Beeton, Metal-o-Turtle, Frogger, Veg-o-Bot, Lady Bug, Bead Worm, Bouncy Boss Robot, Tree Crawler, Sphere-o-Bot, Laser Walker; Sega Retro, Sonic Chaos/Production credits (in-game and US manual credits)
• How it was made: Sonic Retro, Sonic Chaos/Development; Wikipedia, “Sonic Chaos” (Development and release: built on the Master System Sonic 2; EGM award via its Buyer’s Guide); Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sonic Retro, Sonic Chaos/Hidden content (codes, unused content, build dates)
• Firsts: what this game introduced: Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sonic Retro, Sonic Chaos/Development
• Cheats & secrets: Sonic Retro, Sonic Chaos/Hidden content (codes, unused content, build dates)
• Glitches, exploits and oddities: Sonic Retro, Sonic Chaos/Bugs; Sonic Retro, Sonic Chaos/Hidden content (codes, unused content, build dates); Sonic Retro zone pages: Turquoise Hill Zone, Gigalopolis Zone, Sleeping Egg Zone, Mecha Green Hill Zone, Aqua Planet Zone, Electric Egg Zone
• Videos & media: YouTube, Sonic the Hedgehog (SEGA official channel), video FoyoWlOJILc (checked with oEmbed, 5 Nov 2026); YouTube, World of Longplays, video -59vNc4EWm0 (checked with oEmbed, 5 Nov 2026)
• Trivia & facts: Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sonic Retro zone pages: Turquoise Hill Zone, Gigalopolis Zone, Sleeping Egg Zone, Mecha Green Hill Zone, Aqua Planet Zone, Electric Egg Zone; Sonic Retro, Sonic Chaos/Hidden content (codes, unused content, build dates); Sonic Wiki Zone, Sonic Chaos (referenced claims only: Japanese booklet story and profiles, EGM award)
• Legacy: Sonic Retro, Sonic Chaos (story, gameplay, characters, items, versions, re-releases); Sega Retro, Sonic Chaos (release dates, prices, product codes, review index with scans); SEGA, “Sonic Origins Plus – Announce Trailer” (23 March 2023): twelve Game Gear titles, release 23 June 2023
• Sales & reviews: Sega Retro, Sonic Chaos (release dates, prices, product codes, review index with scans); Sega Retro, Sonic Chaos/Reception; Sonic Wiki Zone, Sonic Chaos (referenced claims only: Japanese booklet story and profiles, EGM award); Wikipedia, “Sonic Chaos” (Development and release: built on the Master System Sonic 2; EGM award via its Buyer’s Guide)