Sonic the Hedgehog 2 for the Mega Drive is arguably one of the most famous Sonic titles not just for its place in sonic and gaming history but for content that never made it into the final version that people come to know and love.

This page is an overview as to what was taken out. For more complete and in-depth information there are several excellent websites based on the topic of Sonic game hacking. See the links on Secrets of Sonic games in the Sonic Section front screen for some.


At the time of the games development Sonic the Hedgehog was huge. The press reported on every emerging detail and early screenshots appeared in just about every gaming magazine there was.

At the CES of the summer of July 1992 A beta version (demo / in progress) of the game was on display under some of the tightest security known. Sega decided the version on display was too work-in-progress and disallowed any pictures to be taken. Some pictures were managed to be leaked out.

Sonic 2 Beta Title Screen Final Version Title Screen

Beta Title Screen

Final Title Screen

After the final version was released it became apparent that significant changes had taken place. Much more so than the usual step up from beta to final version generally expected.

From looking at old magazine articles of the games development there were screenshots of sections never to be found in the game, different enemies and the most intriguing was the level select screen. It clearly showed several zones that were not in the final version and had been cut from the game entirely. Additionally a clue was present in the final version. Anybody who went through the sound test noticed that tune 10 was not used anywhere in the game.

Sonic 2 Beta Level Select Final Version Level Select

Beta Level Select

Final Level Select

With Sonic 2 going on to be a huge title one of the best selling 16-Bit titles of all time - the thought of content being left out was almost painful. Fans have long since wondered what these lost zones were actually like amongst the questions as to - why were these taken out in the first place?

This sparked more interest in the final version of Sonic 2 as to how much lost content is actually still in there and not active?

It later became possible to see fragments of one deleted Hidden Palace Zone through the use of an Action Replay (cheat device) which basically showed some garbled graphics.

Years later in 1998 came the leak on to the internet of the Sonic the Hedgehog 2 beta rom. It became possible to play and examine some of the lost levels. It is also possible that there is an alpha Sonic 2 rom.

As such there are plenty of websites with info on the hacking of Sonic 2. One of the most impressive is Sonic Retro (formally SWS2B). This site is devoted purely to Sonic 2. You can download a copy of the Beta from there.


The beta rom image is playable in all Mega Drive emulators as far as Im aware.

It generally plays much the same as the final Sonic 2 game. To access the level select screen simply hold down A and press start on the title screen.

Be advised that this is still a beta and therefore levels are incomplete, buggy and some can not be completed by normal game.

For more exploration the debug cheat is needed.

On the title screen press C, C, Up, Down, Down, Down, Down, Up. If entered correctly you will hear a ring sound. Press A and Start to view the level select. Select a level and hold down A until it appears. When in debug mode the score will become hex numbers.

The game behaves differently in debug mode.

Button A cycles through the objects
Button B toggles the debug mode on and off
Button C place the object on the screen
Button A + C cycles through the objects


This is basically what came to be Aquatic Ruin Zone. Not only was the name changed but its position within the game was also changed from being the 1st zone to the 3rd.


This zone is the most famous zone of them all. It is a mysterious underground area of bridges, tunnels, pipes and water systems. The reasons for its removal from the final game was simply an issue of available room on the cartridge.

It was allegedly designed to be some sort of bonus zone which may have came been Oil Ocean Zone and Metropolis Zone. The zone is over 50% complete in the Beta.

Hidden Palace Zone Hidden Palace Zone
Hidden Palace Zone Hidden Palace Zone
Hidden Palace Zone Hidden Palace Zone

Hidden Palace Zone in the Beta Version

There are significant remnants of this zone in the final version of the game. The zone is selectable and has it own background music BGM10 in the sound test yet there are no graphics or floors implemented.

Action Replay

Enter the code FFFE1 00008. Press start on the title screen and the level will start. You will only start on this level when starting a game until the code is deactivated.

Game Genie

Enter the code ACLA-ATD4. Then enter the level select cheat. Select Death Egg Zone to play.

When selected you simply fall and die against a corrupted screen however, the use of the debug cheat allows for some further exploration though the graphics still remain garbled.

Hidden Palace Zone Hidden Palace Zone
Hidden Palace Zone Hidden Palace Zone

The remnants of Hidden Palace Zone in the final version of Sonic 2

Sonic Jam

Bizarrely the remnants inside the final version of Sonic 2 were also ported for the Saturn version in Sonic Jam. By using a Game Shark / Action Replay and using the code 160FFE10 0800 you can access the zone. The effect is the same as the Mega Drive version: you simply fall and die against garbled graphics.

Curious as to why a deleted zone should be included in a port to a more superior console.

This zone is not to be confused with the Hidden Palace Zone which later appeared later in Sonic and Knuckles. That zone served as an intersection. The real zone from Sonic 2 was much bigger.


As the name suggest this zone takes place in a wood amongst the tree tops.

In the beta version there is a semi-playable first act. There are no enemies, some walls and floors are not implemented and the conveyor belts do nothing.

Wood Zone is completely deleted from the final version of the ROM. There is the smallest remnant found by some superb hackers in the form of the colour palette.

Wood Zone Wood Zone Wood Zone

Wood Zone


This is basically what came to be Mystic Cave Zone yet in its earlier stages of development it was thought that this zone was a completely different design favouring a desert land scape as apposed to a dark cave.

For the Mystic Cave Zone we know there are still some differences. There are several areas which are not found in the final version.

Dust Hill Zone

Dust Hill Zone

There exists an alleged screenshot of the original Dust Hill Zone which shows Sonic running through a desert. This image has never been authenticated.


Very little is actually known about this zone. It is thought that it was an industrial/technological zone similar to the likes of Scrap Brain.

In the Beta version of the game Sonic just falls and dies.

Genocide City

Genocide City Zone

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