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Sonic News Network
Sonic News Network

The Simon Wai prototype of Sonic the Hedgehog 2 (named after the person who discovered it) is a well-known in-development version of the game dating from before the official release of Sonic the Hedgehog 2 itself.

It was discovered on a Chinese GeoCities site before being widely distributed on the Internet. The prototype is frequently examined by hackers to determine how the final game was developed. Since its leak, other prototypes were revealed in varying states of completion.

It was 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.[1] Akinori Nishiyama has also stated that the leak was due to the lack of security at the time.[2]

General differences

  • At this point, Tails is still interdependent. That is, the second player is able to control Tails, except he will also follow Sonic. Also, Tails cannot complete a level on his own, since the game only loads the goal sign when Sonic approaches it. The AI is much simpler; it only follows Sonic and does not try to keep up. Tails loses the player's rings when he is hit. If he dies, he drops back in from the top of the screen and immediately goes into a roll when he hits the ground because he cannot fly yet.
  • If player one completes a level, Tails can be controlled if Sonic is off-screen.
  • As with the Nick Arcade prototype, the Spin Dash is still a work-in-progress, as Sonic and Tails can only charge it up once; the sound for when Sonic spins in the original Sonic the Hedgehog is still heard due to there not yet being a specific sound effect for the Spin Dash.
  • Any zone with water will be glitched when playing in two-player mode, as the game loads the graphics incorrectly.
  • The underwater countdown music uses the Level Select theme. When Sonic gets out of the water, the Emerald Hill music begins.
  • Special Stages are still not present, although the music is.
  • A unique bug is present in this prototype. Upon collecting 100 Rings, the game will play Death Egg Zone's BGM instead of the usual 1-Up sound. This is because sound bank 88 (which was the 1-Up sound in the Nick Arcade prototype) has since been overwritten and not edited to play the correct sound. Game Genie code XCOT-AAC4 will cause the correct tune to play. On the other hand, the monitors were programmed with the correct 1-Up sound.
  • Bubbles are loaded incorrectly from the VRAM.
  • The Sega logo does not appear when booting up the game. However, if the player gets a Game Over, the game does show the Sega logo and then shows the title screen. This also happens if the player waits for the resulting demo to run its course. The sound is also noticeably higher pitched than in the final version.
  • Locking on this prototype with Sonic & Knuckles will unlock the full Blue Sphere game, as it does with the Nick Arcade prototype. This is because the two prototypes have the same serial code as the original Sonic the Hedgehog, which determines the result of the lock-on.
  • As with the Nick Arcade prototype, the timer resets to 9:00 when it approaches 9:59 in order to allow the player to test the stages for extended periods of time.
  • The screen does not scroll up or down when the player looks up or crouches down for a certain period of time.


The Level Select screen.

The prototype is of interest even to non-technical fans as it includes tantalizing hints of a number of extra Zones and features which may have been planned for inclusion in the final game but were eventually cut for one reason or another. Only four of these zones (Neo Green Hill, Chemical Plant, Hill Top and Green Hill) are fully playable and are the zones played through in normal gameplay. The rest are incomplete and can only be accessed via Level Select. The list of the Zones here is as follows from the Level Select menu.

Green Hill Zone

Green Hill Zone was basically Emerald Hill Zone in the final version of Sonic the Hedgehog 2. This is so far the most playable Zone and the only Zone with a boss fight. This Zone was made notable of the Snail Badnik who was scrapped from the final version of Sonic the Hedgehog 2. Ironically, Green Hill Zone is the last Zone of regular gameplay in this prototype version and after the player defeats the boss, the player is whisked back to the title screen.

Wood Zone

Wood Zone

Wood Zone is one of the Zones only to appear in this prototype version of Sonic 2 and then was removed in later beta versions and the final version of Sonic 2. Wood Zone is set inside a giant deciduous forest, which sees Sonic walking along large tree branches and wooden conveyor belts which don't function. However, the level is barely designed and does not contain any Rings or Badnks. Without a signpost or a boss to defeat, it cannot be finished via normal means. Act 2 is empty, causing Sonic and Tails to fall to their deaths.

Metropolis Zone

Much like most of the other zones, Metropolis Zone's level design was absent of Rings and Badniks though its gimmicks and obstacles (the conveyor belts, elevators, crushers etc.) function as they did in the final version of Sonic the Hedgehog 2. However, the lava pits do not damage the player, meaning the player can walk on top of them. Again, there is no signpost or boss to finish the zone via normal means.

Hill Top Zone

Hill Top Zone, in contrast, was only absent of Badniks and both of its acts are fully playable. Object wise, the gondolas and seesaws function properly but the tunnels do not curl Sonic into his spinball form. Act 2 also appears to end at an earlier point.

Hidden Palace Zone

Hidden Palace Zone

The formerly unfinished Hidden Palace Zone in Sonic the Hedgehog 2 was planned to be a cavern filled with jewels. It has been compared to Sonic the Hedgehog 3's IceCap Zone due to graphical similarities. Hidden Palace took its name from the underground cavern near Mt. Arakai in central Japan. It is filled with precious stones, as well as ancient rock formations.

In earlier versions of the unfinished Sonic the Hedgehog 2 (the first of which was stolen from a game show in 1992 according to Yuji Naka[3]), Hidden Palace is an incomplete level. Act 2 (as well as Act 3 in the prototype discovered by drx) starts with Sonic stuck inside a wall, and using Debug Mode to move Sonic outside the wall reveals that the act is identical to Act 1, but without any objects. Neither act of Hidden Palace Zone can be completed, as there are no signposts or capsule. Using Debug Mode allows the player to get into a second part of the level, due to a steep slope that cannot be climbed up.

Hidden Palace Zone was one of the earliest Zones shown to the public during the production of the game. It appeared alongside the famous Dust Hill Zone in two mock-up images that were some of the earliest images shown for the game. The area in the mock-up is found in the beta, and via ROM hacking, the triceratops Badnik was also found to still be present in the game data. The game was continually used in promotion for some time. Time issues and overall fun factor have been stated as reasons for cutting the level.

There are three areas that cannot be reached without Debug: a small underwater area that leads to an item box (shortly after you leave the tube, it is under a patch of green floor which looks similar to the breakable floors in the Marble Zone of Sonic the Hedgehog), a tube that leads to death below the large emerald, and an area past the slope that cannot be accessed on foot. The latter is assumed to be the top of that slope. It has water slides on it like some areas of the Labyrinth Zone, but Sonic does not slide down the water. At one end is the top of the slope, and at the other just water and an empty space that leads to the edge of the map. A fourth area is in fact accessible without Debug Mode, though it is difficult to reach, requiring the player to jump to a platform directly below the one he/she is standing on.

The level features a large emerald above a tube, which has caused much confusion and speculation, as many have confused it with the Master Emerald, the equally large emerald guarded by Knuckles the Echidna that keeps Angel Island afloat. The level designer however revealed that it was simply just a breakable object, similar to the rocks in the Hill Top Zone or Angel Island Zone, only with a specific purpose.[4]

There is a 1-Up Monitor in the level displaying a Tails icon box, leading some to speculate that the level was a Tails-only level though Sonic still receives an extra life as it were a regular 1-Up. However, suggestions have been made that the level was also connected to Super Sonic; one by a member of the Sonic the Hedgehog 2 team.

Oil Ocean Zone

Oil Ocean Zone more or less retains the same appearance in the final version of Sonic the Hedgehog 2. Act 1 is almost fully playable apart from the absence of a signpost. This Zone features a unique mechanic where relatively small checkered balls (similar to the one used by the first boss of the original Sonic the Hedgehog) spring up and roll along the floor when a nearby switch is pressed. The player can stand on top of these. However, should they fall directly onto the player, he/she will lose a life. Curiously, they seem to ignore any elevation and move onto upper platforms as it were on the same ground level but they can throw the player into the ocean. These objects were cut in the final version of Sonic the Hedgehog 2 but can be placed in Debug Mode.

Dust Hill Zone

In this prototype, Dust Hill Zone was basically Mystic Cave Zone in the final version of Sonic the Hedgehog 2. The level layouts of both acts pretty much replicate that of the final version of Sonic the Hedgehog 2 but is devoid of any Rings, Badniks and regular means of completing the Zone. Notably in Act 1, there appears to be objects placed somewhat randomly, most likely for testing purposes but they appear only in the first half of the act as the second half is absent of such objects.

Casino Night Zone

Casino Night Zone

Casino Night Zone looked completely different in this prototype compared to the final version of Sonic the Hedgehog 2 as landmass features received pinkish coloring and sky blue floors with French card symbols on them and the background is drastically different. Again, the Zone is absent of Rings and Badniks and there are notorious gaps leading to bottomless pits which the player could fall through and lose a life. There are no elevators in the Zone as well and the Bumpers that give 10 points are also missing. In Act 2, the background is overwritten by the pinball table graphics.

Chemical Plant Zone

Chemical Plant Zone is fully playable apart from the absence of Badniks. The tubes still function as intended in the final version of Sonic the Hedgehog 2. It is worth noting that the blue sludge that travel from one pipe to another makes a different sound effect and the loops have slanted corners instead of perpendicular corners. Also, the small platforms that move the player across rails are much smaller in width.

Genocide City Zone

Genocide City Zone was intended to be a graphical change of Metropolis Zone. According to a Tom Payne interview, the meaning behind the name is due to the Japanese team members wanting to make the zone sound dangerous in English, resulting in the alternate name "Cyber City" in concept.[citation needed] It was planned to be a single zone, but due to time constraints, the remaining zone ended up as Metropolis Zone Act 3. The graphics were also confirmed to being reused in Sonic the Hedgehog Spinball. In this prototype, the level is completely empty which will cause Sonic and Tails to fall to their immediate deaths.

Neo Green Hill Zone

Neo Green Hill Zone was basically Aquatic Ruin Zone in the final version of Sonic the Hedgehog 2. While its two acts are completely playable, there are no enemies present and the only obstacles present are the arrow-shooting totems. Whenever the player enters the underwater areas, the splashing animation is corrupted and shows misaligned Air Bubbles instead of a splash. It appears that the underwater segments of the Zone were not fully implemented yet, most notably at the beginning of Act 2 where if the player falls off the swinging platforms, they will die.

Death Egg Zone

The presence of Death Egg Zone in the Level Select list with two levels in this prototype shows that the Death Egg Zone could have been a full-length zone with two acts. However, the prototype version of the level has nothing in it like Genocide City Zone, causing the player to fall to their immediate deaths.

Other features

Unused sprites

Sprite Description
Animated drills for Metropolis Zone
Two unused vines, one being a switch, that Sonic/Tails hang on to. They have no code, however.
Sonic2 waiproto-ChikiChikiBoysLeftover1.gif
Sonic2 waiproto-ChikiChikiBoysLeftover2.gif
Sprites of a fireplace leftover from Chiki Chiki Boys.
The mystery Item Box, which did not work in the Nick Arcade Prototype, has a function of bestowing Super Sonic.

Cheat codes

  • Level Select: At the title screen, hold A Button (Sega Genesis).svg and press Start.
  • Debug Mode: At the title screen, press the following in order C Button (Sega Genesis).svg, C Button (Sega Genesis).svg, Up, Down, Down, Down, Down, Up. Then activate the Level Select code then while highlighting a level, hold A Button (Sega Genesis).svg while pressing Start to start a level with Debug Mode enabled.
  • Night Mode - At the title screen or Level Select, hold C Button (Sega Genesis).svg while pressing Start at a highlighted level.
  • Two-Player Mode - At the Level Select, hold B Button (Sega Genesis).svg while pressing Start at a highlighted level.


  • The Simon Wai prototype uses the same title screen from the Nick Arcade prototype.
  • Hidden Palace was one of the first Zones to have its name used more than once in the series. Another was Death Egg Zone, appearing in Sonic the Hedgehog 2 and Sonic & Knuckles. After that was IceCap Zone, in various forms present in Sonic the Hedgehog 3 and Sonic Adventure (like Lava Reef Zone and Red Mountain, the difference seems to be that of the interior and exterior). The next Zone was Sky Chase Zone, in Sonic the Hedgehog 2, Sonic the Hedgehog Pocket Adventure, and Sonic Adventure (as a two-act mini game). Finally, there was Angel Island Zone, appearing (also in different forms) in Sonic the Hedgehog 3 and Sonic Advance.
  • There is a mock-up of the level which has Sonic off-center and the HUD used the same text font as Sonic the Hedgehog.
  • Hidden Palace remains virtually unchanged from the Nick Arcade prototype. It seems that Hidden Palace went a long time without development, as it was decided that finishing the other zones took priority.
  • In Hill Top Zone Act 2, it is possible for the player to get stuck when finishing the goal. By touching the signpost and then dropping down to the lower ground before the controls lock themselves, Sonic is forced to continue moving to the right and cannot jump back to the upper ground.
  • Most of the sprite assets from this prototype were added as Debug Mode assets in the 2013 mobile release, with the notable exceptions being Gator and BFish, which were scrapped entirely, and Jellygnite, which was added.


  1. GameSpy: Sega's Yuji Naka Talks!. GameSpy Xbox. Gamespy. Archived from the original on 4 November 2005. Retrieved on 2 September 2018.
  2. Kikizo Games: Game Features: Sonic Team Interview November 2005 (Page 2). Kikizo Ltd (30 November 2005). Archived from the original on 3 December 2005. Retrieved on 2 September 2018.
  3. Sega's Yuji Naka Talks!. GameSpy Xbox. Gamespy. Archived from the original on 4 Novemer 2005. Retrieved on 2 September 2018. "You see, back in mid-1992 we had taken a demonstration cartridge to a toy show in New York. It wound up being stolen, and although we searched and searched all over, it was never found."
  4. Stitt, Craig (23 January 2001). Interview with Craig Stitt. ICEKnight. Archived from the original on 22 March 2005. Retrieved on 2 September 2018.

External links

Main article (Knuckles in Sonic 2) | Staff | Manuals | Glitches | Beta elements | Gallery | Pre-releases (Nick Arcade, Simon Wai) | Re-releases (2006, 2013, 3D, Sega Ages)