Sonic the Hedgehog 2


 * For the Master System and Game Gear game of the same name, see Sonic the Hedgehog 2 (8-bit).

Sonic the Hedgehog 2, or simply Sonic 2, is a platform game developed by Sonic Team in collaboration with Sega Technical Institute, and published by Sega for the Mega Drive/Genesis. It was released in Japan on November 21 of 1992 and in North America and Europe three days later on November 24. It is the sequel to Sonic the Hedgehog and was followed by Sonic the Hedgehog 3 in 1994. The game introduces Miles "Tails" Prower as an addition to the cast and a new playable character. The game follows the effects of the 8-bit version which was released earlier.

The story follows Sonic the Hedgehog and Tails on their mission to stop the evil Doctor Robotnik from stealing the Chaos Emeralds to power his Death Egg. Sonic and Tails must defeat Robotnik's army and free their friends.

Six months after its release it had sold around six million copies and became the best selling game on the Mega Drive. The game was compatible with Sonic & Knuckles ' lock-on feature which allowed the player to play as Knuckles in Sonic 2. It has been included in a number of compilation packages on a range of platforms; on June 11 2007, the game was made available on the Nintendo Wii's Virtual Console, and released for Xbox Live Arcade on September 12 2007.

Storyline
At the end of Sonic the Hedgehog, Dr. Robotnik's Scrap Brain facility was destroyed, but the evil doctor narrowly escaped.

Now Robotnik is back and plans to conquer the world once more. He secretly follows Sonic's biplane, the Tornado, to his vacation spot, West Side Island. According to legend, an ancient civilization once abused the power of seven "power stones" on West Side Island. Sonic meets a peculiar two-tailed fox named Miles Prower, better known as "Tails". The two become good friends. Meanwhile, Robotnik begins his search for the Chaos Emeralds to fuel his new Death Egg warship. One afternoon, he launches his full-scale attack on the island. He imprisons all of the animals of the island and turns them into mindless worker drones called Badniks. Fortunately, Sonic is determined to thwart the Doctor at all costs. This time, he isn't alone, as Tails decides to aid him. Together they must locate the Emeralds before Robotnik does, and stop him before the Death Egg is complete.

Single player


The gameplay of Sonic the Hedgehog 2 builds upon the basic set-up of the original Sonic the Hedgehog game. The player finishes each level, generally moving from left to right, within a time limit of ten minutes. Along the way, rings are collected and Badniks are defeated. Star posts serve as checkpoints, where if the player were to lose a life then he or she would return to one. When the player has collected at least 50 rings, star posts can be run past for an optional Special Stage. At the end of Act 2, Sonic confronts Dr. Robotnik, although there is an exception in the Metropolis level in which there are 3 stages.

Although zones have grown significantly in size since Sonic the Hedgehog, they now consist of two acts instead of three (with the exception of the Metropolis Zone, which has three acts, and the three final zones, which each have one), and there is greater emphasis on variety between levels. The gameplay has also become even faster; to that end, Sonic is able to perform a new special move referred to as the Spin Dash Attack. The Spin Dash attack allows Sonic to spin in place, as if revving up an engine, before taking off at high speeds from a stationary start. Sonic's running motion also features longer strides.

Special Stages track Sonic from behind while he runs through a (semi-) three-dimensional half-pipe course filled with rings and bombs. A certain amount of rings must be collected to pass through two checkpoints and then obtain the emerald itself. If the player runs into one of the many bombs (increasing in number as the emeralds are captured) he will lose a set amount of rings, varying depending on the stage. The order of stages is fixed in rising difficulty, and Sonic cannot enter the next stage without passing the previous (unlike Sonic 1). Whether the player is able to obtain the emerald or not, Sonic is transported back to the last star post he hit in the zone when the special stage is over and has zero rings.

From the options menu, players can select to either play as Sonic alone, Tails alone or Sonic and Tails. By default, players control Sonic while Tails tags along unhindered. However, a second player may control Tails separately. Should Tails move off-screen, he will eventually return.

Stages

 * Emerald Hill Zone
 * Chemical Plant Zone
 * Aquatic Ruin Zone
 * Casino Night Zone
 * Hill Top Zone
 * Mystic Cave Zone
 * Oil Ocean Zone
 * Metropolis Zone
 * Sky Chase Zone
 * Wing Fortress Zone
 * Death Egg Zone

Super Sonic
Obtaining all seven Chaos Emeralds by clearing all of the special stages will unlock a new feature; Sonic's ability to change into Super Sonic. Sonic changes into his "Super Form" when he has collected at least 50 rings and jumps into the air. At this point, he glows yellow and is virtually invincible, although he can still get killed by drowning, getting crushed, falling off the screen, or running out of time. His speed, acceleration, and jump height are all increased as well. This means that it is much more difficult to control Sonic in this form, especially when the player needs to make precise jumps. However, his Spin Dash Attack is decreased in effectiveness as the initial velocity is decreased rapidly. Super Sonic consumes one ring per second, and when he has no rings left or he reaches the end of the act, he reverts to his normal state, severely crippling the player as they are left with no rings.

If the game is played with Tails only and the player manages to collect all of the Chaos Emeralds, nothing happens.

Two player
In two player versus mode, players compete against each other - either as Tails or Sonic - in a split-screen race through three regular zones and one special stage. Regular zones include Emerald Hill, Casino Night and Mystic Cave and have different music from their one player counterparts, while the Special Stage is similar to the Emerald Stage in single player. In the regular levels, players are ranked in five areas (score, time, rings held at the end of the level, total rings collected, and number of item boxes broken), with the player scoring highest in the most levels winning the round, while in the Special Stage, players compete to obtain the most rings. Once one player finishes one of the regular levels, the other player must finish the zone within 60 seconds or lose a life.

In case of a tie, an additional Special Stage round must be completed. Also, to heighten the stakes, there are two unique items in versus-mode: a teleport item that instantly switches positions between players in a zone, and a Robotnik item that damages the unlucky player. Furthermore, an optional setting allows that all item boxes in two-player mode are only teleports.

Special Stages
In Sonic 2, there are 7 special stages. When Sonic has collected at least 50 rings and he hits a Star Post, a red halo of stars will briefly float above it, which Sonic can then jump through to get to a special stage.

Special Stages track Sonic from behind while he runs through a three-dimensional half-pipe course filled with rings and bombs. A set amount of rings must be collected to pass through three checkpoints and eventually obtain the emerald itself. The order of stages is fixed in rising difficulty, and Sonic cannot enter the next stage without passing the previous (unlike Sonic 1). Whether the player is able to obtain the emerald or not, Sonic is transported back to the last lamp post he hit in the zone when the special stage is over and has zero rings.

Bosses
Robotnik appears in his customized Eggmobiles at the end of each Zone. This means, he will usually appear at the end of each second Act, except in the Metropolis Zone (which has three Acts) and the Death Egg Zone (which has only one). Eight hits are required to defeat each boss.


 * 1) Drill Eggman (Emerald Hill Zone)
 * 2) Water Eggman (Chemical Plant Zone)
 * 1) Hammer Eggman (Aquatic Ruin Zone)
 * 2) Catcher Eggman (Casino Night Zone)
 * 3) Submarine Eggman (Hill Top Zone)
 * 4) Drill Eggman 2 (Mystic Cave Zone)
 * 5) Submarine Eggman 2 (Oil Ocean Zone)
 * 6) Flying Eggman (Metropolis Zone Act 3)
 * 7) Barrier Eggman (Wing Fortress Zone)
 * 8) Silver Sonic (Death Egg Zone)
 * 9) Death Egg (Final Boss of Death Egg Zone)

Development and release
While Sonic the Hedgehog was designed by Sonic Team in Japan, development duties for Sonic 2 were handed over to Sega Technical Institute in the United States. However experienced Japanese Sega members such as Yuji Naka and Hirokazu Yasuhara (the first game's lead programmer and game planner respectively) were brought in to work alongside the American developers.

Prototype versions
Main article:Sonic 2 Beta 

A prototype of the game, dating from before Sonic 2 itself, was discovered on a Chinese GeoCities site and has been widely distributed on the Internet. Only four levels can be played in "normal" gameplay; the rest (including several incomplete stages) have to be accessed through the level select code. Many are not entirely playable, but can be explored using the debug code. The prototype is frequently examined by hackers to determine how Sonic the Hedgehog 2 was developed. It was recently stated in an interview with Yuji Naka that this beta was from a demonstration cartridge that was stolen at a toy show in New York in 1992. Akinori Nishiyama has also stated that the leak was due to the lack of security at the time.

In Asia and Brazil, the prototype version was put on cartridges and passed off as the final version by pirates who have altered it slightly to stop the Sega logo from showing when the game boots up, as was common practice.

Game Gear/Master System version
A game also entitled Sonic the Hedgehog 2 was released for the Master System and Game Gear consoles shortly before the release of the Sega Mega Drive version. Although the names are the same, the storylines, zones and gameplay are different.

The Slip and Fall Wall
In Sonic 2 hook Sonic and Knuckles on, then play Knuckles in Sonic 2, then get to Chemical Plant Zone. Once there, climb up the first wall you see, then Knuckles will fall off.

Sonic may move through walls in Chemical Plant Zone, the wall acting like spikes.

Releases
The game was released in Japan for the Sega Mega Drive on November 21 1992. The Sega Genesis release in the United States and the European Mega Drive release came three days later on November 24, a Tuesday, and the release day was dubbed "Sonic 2s day". Sega claims that they sold 400,000 copies of Sonic 2 in the first five days after release. It has since been re-released as part of the following compilations:

Sonic 2 with Sonic & Knuckles
Knuckles the Echidna in Sonic the Hedgehog 2 is a game activated by locking Sonic the Hedgehog 2 to the pass-through cartridge of Sonic & Knuckles that was released later by Sega. The resulting game is almost identical to Sonic the Hedgehog 2, except that one plays as Knuckles the Echidna. As Knuckles has abilities and weaknesses that Sonic and Tails do not, the game is an overall different experience. Knuckles can glide and climb walls, which allows him to access areas otherwise unreachable by Sonic and Tails, while his weaker jumping abilities make some situations, such as certain boss fights (particularly the final boss of Death Egg Zone), more difficult. The two-player mode and options screen have also been removed. Players who are most familiar with the level layouts in Sonic 2 will notice a few minor differences. Unlike in the default game, when a player activates a star-post and enters the special stage, the ring count remains upon returning to the regular stage.

Reception
Due to the popularity of its predecessor Sonic the Hedgehog, Sonic 2 already had an established fanbase anticipating its release. The release of Sonic 2 was the main reason that Sega caught up to Nintendo in the "console wars". It brought their market share up to 50% within six months of its release. It went on to be the best selling game for the Mega Drive/Genesis, selling around six million copies altogether. It was well received by most gaming reviewers. It was praised for its large levels, colourful graphics and backgrounds, increased cast of characters and enemies alike, and music. Gamespot stated that "Time may have eroded Sega's prominence, but it hasn't done much to diminish how sweet Sonic the Hedgehog 2 is." and, along with other reviewers, commented on how it is still a fun game to play.

The game's main criticism's were of the two player mode that was a new introduction to the series. It suffered from slow down and some visual problems such as flickering and the small area for each player. It only offered four different zones that could be played with two players.