Sonic Chaos

Sonic Chaos, known as Sonic & Tails (ソニック&テイルス), is a video game for the Sega Master System and Sega Game Gear, developed by Aspect and published by Sega in 1993. It was the last platform based Sonic game released for the Master System in Europe.

It was re-released in 2004 as an included game in Sonic Mega Collection Plus on the PlayStation 2, Xbox and PC, and is also included as an extra on Sonic Adventure DX: Director's Cut for the Nintendo GameCube and PC. To unlock the game, the player has to collect a total of 60 Emblems with all of the playable characters. All these re-releases are the Game Gear version; the Master System version would not be released until 2009 for the Wii Virtual Console.

Sonic Chaos is notable for the fact that it is the first 8-bit Sonic title to feature Tails as a playable character and also the first in the series to allow the player to manually control his flight.

Storyline
The storyline to Sonic Chaos, like most Sonic stories, revolves around Dr. Robotnik and his quest for world domination via the mythical Chaos Emeralds. The Emeralds are the source of vitality for all living things, but they could be turned into nuclear bombs and laser weapons in the hands of the rotten Dr. Robotnik.

Dr. Robotnik has stolen the red Chaos Emerald, causing the other five to "lose balance" and scatter themselves into a parallel universe. As a result of the instability, South Island is now sinking into the ocean. It is up to Sonic and Tails to find the Chaos Emeralds and restore harmony to the universe, or else the innocent residents of South Island will find themselves taking a long swim.

Gameplay
Overall, the gameplay is similar to previous 8-bit Sonic games. However, as stated above, players can control Tails as well as Sonic this time. Sonic now comes equipped with the Spin Dash attack, performed by holding the directional pad down to crouch and pressing action to gain stationary speed. When the down button is released he shoots forward curled in a ball, hurting any Badniks that he comes in contact with while in this state (spikes and other obstacles do, however, still hurt).

By holding up instead of down, and then pressing action, Sonic will start running in place. By releasing up he will then zip forward in a running fashion, moving faster than the Spin Dash allows him to. This is called the Strike Dash, which is also in Sonic the Hedgehog CD (known as the Super Peel Out in that game, and therefore this move is usually referred to under that title). However, Sonic will quickly stop unless the directional pad is held whichever way he was going. The big advantage to the strike dash is that he is invincible for a short distance, and "strikes" an enemy he passes through. However, one of the main disadvantages of the Strike Dash is that Sonic is vulnerable to enemy attacks after the brief invincibility wears off. Also, Sonic has more volition while rolling, so he does not slow down as quickly, but rolling uphill is more difficult than running uphill. This means the faster way to go downhill is the Spin Dash, but the faster way to go uphill is the Strike Dash. Sonic also has the job of finding the six Chaos Emeralds. Unlike other 8-bit Sonic games, the Chaos Emeralds are located in Special Stages. In order to enter a special stage, Sonic needs to collect 100 Rings in one act (you'll still be awarded the extra life for collecting 100 Rings). Sonic Chaos is also unique amongst all the Sonic games in that the special stages each have a different look. Challenges include flying towards an Emerald on rocket boots, hopping up various platforms on a spring, and navigating through a maze of pipes. Successfully complete the Special Stage to get a Chaos Emerald, but lose the Special Stage and Sonic goes straight to the next stage in the game as normal, without the emerald. Robotnik himself holds the sixth Chaos Emerald, and you need to beat him in order to win it back.

Playing as Tails is slightly different but generally easier. Not only can Tails fly (performed in the same way as Sonic's Strike Dash), but he starts the game with more lives and continues. Additionally, the player can not collect the Chaos Emeralds when playing as Tails; when he has 100 rings, he simply earns an extra life and the level continues. Tails can perform the Spin Dash in the same way Sonic can, and when he finds an item box that would normally contain rocket shoes, he gains a speed boost instead.

Zones
In total there are six zones to complete, each one consisting of three acts of which the final act is a boss battle.

In order, the Zones are:
 * 1) Turquoise Hill Zone
 * 2) Gigalopolis Zone
 * 3) Sleeping Egg Zone
 * 4) Mecha Green Hill Zone
 * 5) Aqua Planet Zone
 * 6) Electric Egg Zone

Bosses

 * 1) Lady Bug Boss (Turquoise Hill Zone)
 * 2) Bead Worm Boss (Gigalopolis Zone)
 * 3) Bouncy Boss Robot (Sleeping Egg Zone)
 * 4) Tree Crawler Boss (Mecha Green Hill Zone)
 * 5) Sphere-o-Bot Boss (Aqua Planet Zone)
 * 6) Laser Walker (Electric Egg Zone)

Differences
The Master System version was released first, followed by the Game Gear version the following month. Differences include:
 * The resolution was again lowered with little regard for the overall viewing area - for instance, a ring that flies straight into the air upon getting hit will hit the "out of bounds" area at the top of the screen, resulting in it disappearing.
 * Compared to the previous entries, this game takes slightly more advantage of the Game Gear's increased color range - for instance, the unique peach and brown checkered soil of Turquoise Hill was changed to the series' now-familiar orange and yellow pattern, and the green skyline with pink streaks (likely indicating foggy pollution) of Mecha Green Hill was changed to a pink hue with green streaks.
 * The title screen and character select screens were changed, as well as the zone title card fonts.
 * Between the console and handheld versions, some music tracks were mildly rearranged. This is probably most noticeable when listening to the Turquoise Hill, Sleeping Egg and Aqua Planet themes back-to-back, but in the case of Gigalopolis Zone the theme was entirely rewritten.
 * The track that plays when claiming a Chaos Emerald was removed, but music was added to the Power Sneakers power-up (which was oddly missing, with no tempo effect). The intro was also given an original piece rather than the Electric Egg theme.
 * The bosses appear to be a bit redrawn to make up for the smaller viewing area, being stretched a bit taller.
 * There are layout changes in the Act 3 of most (if not all) zones.
 * The Gigalopolis Zone boss may no longer shoot a spiked ball upon defeat in the Game Gear version.
 * The Mecha Green Hill boss is no longer over a pit of spikes, instead fighting over flat ground.
 * After the final boss is cleared and Robotnik escapes, the usual victory animation and theme plays rather than the screen simply fading to white.
 * Sonic originally rolled during the bad ending in the Master System version; in the Game Gear version, Sonic is instead walking then trips as he begins to run after Robotnik.
 * In the Master System version, Tails' name is written as "Miles Power" instead of "Miles Prower" during the credits' cast. The Game Gear version corrects this mistake.
 * The Game Gear release had regional differences of its own - the Japanese version changed the font yet again, as well as the title screen and replaced the Robotnik name with Eggman in the cast roll. On the other hand, it retained Gigalopolis Zone's name - other releases changed it to Gigapolis Zone.

Reception
Sonic Chaos received mixed to positive reviews. Critics praised the gameplay, level design and the ability to play as Tails, but criticized the overall length of the game and its simple graphics. Despite these criticisms, Sonic Chaos was awarded Best Game Gear Game of 1993 by Electronic Gaming Monthly.

Sequels
As a follow-up to Sonic Chaos, Sega released Sonic the Hedgehog Triple Trouble in 1994. The game was exclusive to the Game Gear console and entitled Sonic & Tails 2 in Japan.

Trivia

 * This is the first Game Gear/Master System game in which Tails is playable, and the first game in the series in which the player can control his flight.
 * This was the first game in the series to actually show how fast the player was moving through zones with a Km/h Speedometer sign post at the end of each act. Only two other Sonic games have adopted this: Sonic Labyrinth and Sonic Unleashed.
 * The background music for Mecha Green Hill Zone is a remix of the Green Hills Zone music in the previous 8-bit version of Sonic the Hedgehog 2, which was also remixed into the main theme of Sonic CD: "Sonic - You Can Do Anything". Similarly, this game's final boss theme is an arrangement of the previous game's boss theme in the Game Gear version, which was remixed as Metallic Madness.
 * When accessing the Sound Test Feature in the game, "BGM#09BH" is a track that was never played through the entire game. Interestingly, it was later used in Sonic Triple Trouble as the Sunset Park Act 3 song.
 * The title and life lost tunes from the 8-bit version of Sonic the Hedgehog 2 are reused in a higher pitch.
 * The Japanese Game Gear manual adds that Sonic and Tails were on one of their adventures when they overheard Robotnik's plan of seeking the Emeralds in South Island once again. This prompted their return to the peaceful island, only to find it in total chaos. This detail is not in other releases.