Sonic the Hedgehog 2 for the Sega Mega Drive / Genesis is a fantastic game and I have fond memories of it.
Below is the complete collection of beta and prototype builds of the game (versions before the final version was released to the public) that have been found and descriptions for each one.
The controls are the same for each game:
Arrow keys = Move
Enter = Start/Pause
Z, X or C = Jump
Hold Down Arrow & a Jump Key to perform a Spin Dash
Full Screen mode – Choose the last option on the bottom left of the screen as you hover your move over it.
Sonic 2 Beta – Nick Arcade prototype
The Sonic the Hedgehog 2 “Nick Arcade” Prototype is a prototype build of Sonic the Hedgehog 2 for the Sega Mega Drive. It stands as the earliest version of the game to be found and released onto the internet, likely created during the first half of 1992.
While perhaps unlikely to have been built for the show, this release is commonly referred to as the “Nick Arcade” prototype due to its appearance in two 1992 episodes of Nick Arcade – the first sightings of the prototype by the Sonic the Hedgehog community.
It is also known to have been shown in issues of Sega Visions and, potentially, a behind closed doors press-only event at Summer CES 1992.
The Nick Arcade prototype is an extremely early version of the game. Only an untitled Emerald Hill Zone can be played normally, with a further five zones accessible only through a level select code.
Much of the game still looks and plays like the original Sonic the Hedgehog – the level select screen is identical, and remnants of the original Green Hill Zone are still somewhat playable.
Sonic 1 music is still intact, and the full Blue Sphere game is available when locked on to Sonic & Knuckles.
The title screen is the same as the Simon Wai Prototype, Beta 3 and Beta 4.
Sonic bounces back off a wall if he runs into it with a high velocity
If Sonic runs into a wall with a high velocity, he will bounce back off of the wall. This feature was canned sometime after this build, but the sprites it uses are still present in the Simon Wai prototype.
Each Zone uses music from Sonic 1, further proving that Sonic 2 was built from Sonic 1.
There is a large amount of raw code contained within the ROM.
Tails can lose rings for the player if he is hurt, just like in the later beta.
If Tails dies, the camera will follow him as he respawns until he goes off screen.
If Sonic & Tails are hit at the same time, lots of rings will sprawl out regardless of how many rings they actually have (provided the player has at least one ring).
The backgrounds of Hill Top and Chemical Plant don’t move.
Invincibility doesn’t show stars, but plays the music. The music and invulnerability lasts until the end of the act.
Try jump without rolling in a spring pointing to down and Sonic will use the dying animation while falling. (Tested in Emerald Hill)
The ground speed cap has not yet been removed.
Green Hill Zone
This Zone from Sonic 1 is still available, with its level art converted to Sonic 2’s format (128×128 blocks rather than Sonic 1’s 256x256s) and the necessary changes have been made to make loops work.
Collision detection is very glitchy, as the collision system has been changed to the system for Sonic 2, but Green Hill Zones collision pointers are still set up for Sonic 1s’ collision. Oddly, the old Sonic 1 collision index still exists in the rom, and can be restored via cheat codes (doing this will fix Green Hill Zone, but cause similar collision issues in every other zone in game).
Tails Life Monitors are present just as one is in Hidden Palace Zone, as all the monitors in Green Hill Zone haven’t been changed to use Sonic 2s’ monitor system. As a result, nearly every monitor in Green Hill Zone has been “switched” with a different monitor.
You can see here that the Sonic 1 springs still are here in the game and fully functional; the springs in the Sonic 2 levels are different and match the final game.
Many badniks and obstacles use glitchy sprites, including rings.
The Crabmeat badnik uses a lost sprite from Sonic 1.
If one passes into Marble Zone (Chemical Plant Zone), the rings will still use the glitchy sprites they had in Green Hill Zone.
The spikes used are the same ones from Sonic 2. They use the correct graphics (aside from the green outlines) when seen in Debug Mode but use glitchy graphics when placed or seen in normal gameplay.
The boss for the zone also uses glitchy sprites, as well as using the same lost sprites as the Crabmeats in place of Robotniks’ face.
Tails can stand on the spikes without getting hurt.
This is Chemical Plant Zone, and it is heavily under development, with major differences in the level’s design from either final or the later prototypes, and is very unfinished.
Chemical Plant Acts 2 and 3 have the same layout as Act 1, but have the ring and object layouts of Green Hill Zone 1.
It uses a pink palette instead of a green palette used in the later betas and final versions.
Some of the buildings in the background are shorter, and match that of the footage of the Nick Arcade build.
There are extra objects in the zone for Marble Zone in Sonic 1 accessible via debug, but they use garbled tiles.
There is a falling block for Chemical Plant also accessible via debug
The transportation tubes were apparently used in a different way, but they aren’t functional in this build.
There is a prototype boss for this zone found in the ROM through hacking.
The unused RAW data contained with the ROM is loaded when you down the zone.It does a illegal instrucion error.
It loads if Tails falls to the area too.
Spring Yard Zone
Actually Hidden Palace Zone, the zone layout is as it is in the later Simon Wai prototype.
Act 2 has some leftover object placement from Green Hill Zone Act 2.
There is a third act which has water that constantly rises and falls. This zone loads Green Hill Zone Act 1’s ring locations.
If under water in Acts 2 and 3 until the countdown starts and you jump out the Labyrinth Zone music will play.
The level of water can be controlled using Up and Down on the 2P controller.
If you move the water up so a badnik is submerged, his orange spot turns bright yellow. This is because Sonic’s underwater palette is really from Labyrinth Zone in Sonic 1.
In Act 3 you get placed in the blocks, what makes the camera go crazy (after some button mashing you will eventually get placed into the level)
In Act 3, shortly after you exit the tube, the water will suddenly appear.
All of the debug mode objects besides rings and monitors have broken previews.
There is a strange bouncing object using bat’s graphics found in the debug list.
It has two objects that uses the animals’ graphics. One only flips, other flips AND shoots fire.
The other one looks like the unused Tycerobot.
An empty zone, it loads Marble Zone’s ring layout, Chemical Plant Zone’s artwork, and has Labyrinth Zone’s rippling effect. Third act is as SBZ3.
Labyrinth Zones layouts are very broken, and seems to load broken data from Chemical Plant alongside leftover garbage data.
Using debug mode several people have found various strips of “land” but that data is often still just garbage.
Several people have debated that this could supposedly be an early version of Genocide City Zone (because of the city-like rippling lines that overlap your character) but somehow got removed from the Simon Wai Prototype. However, it’s more likely just garbage data leftover from Sonic 1, as this zone doesn’t have any of its own data, besides that which is leftover from Sonic 1.
If Marble Zone (CPZ) is loaded first, going back to the level select and going to Labyrinth Zone will cause it to load Chemical Plants background and some of its layout. (some layout tiles are mysteriously missing though)
Scrap Brain Zone Act 3 does the same thing, although it loads its own palettes. Oddly, you can easily land on solid ground in SBZ3 if you do this trick, and you can actually go forward by quite a bit (getting to the top of the level and beating it is impossible, though).
Star Light Zone
Actually Emerald Hill Zone (which the later prototype confirms kept the name Green Hill Zone for a time) and is as the same as it was in the Nick Arcade video. The layout is very different in Act 1, and slightly different in Act 2. Star Light Zone music plays in this zone.
This is the only zone where Tails is disabled, suggesting this particular version was tailored for the Nick Arcade show in order for the contestants not to have their rings lost by Tails, as well as hide the fact that he can follow the player, as this feature hadn’t been directly featured previously.
Tails can play in this zone via 2 player mode, though.
The boss behaves exactly the same as in the later prototype, but it does have explosion effects. These are the same as the ones from Sonic 1.
The 4th buzzer’s shots (and every other buzzer past it in the level) rarely hurt the player.
Scrap Brain Zone
Actually Hill Top Zone, this zone is also under heavy revision, as it finishes with a pipe leading to instant death because the screen-limit hadn’t changed yet.
The playfield limits are still the same as they were in Sonic 1, but the level does not end at these limits. As a result, Act 1 cannot be played through.
The secondary collision array for Act 2 is missing, so as a result, loops don’t work.
Second act crashes at about the midpoint. This is because, as Sonic 2 is built off of Sonic 1, the level event handler calls a subroutine from Sonic 1 that no longer exists (the transition between Acts 2 and 3 of Scrap Brain Zone). Final Zone crashes at the second tree for the same reason.
The lava doesn’t hurt you in this prototype.
Green orbs are used as the weight on teeter-totters instead of a Sol without fireballs.
The lifts are not fully functional yet and partly broken
It is possible to move Tails past the point in Act 2 where it crashes and drop down, transporting you to Act 3.
Hill Top Zone (matching behavior in Sonic 1, where Final Zone is tucked into a corner of SBZ2), crashes to pink if you continue onwards because the game is trying to access the Final Zone boss data which is not there, dead end backwards. If you use debug and continue past the second tree, when you see the pink screen, rapidly press C, at the top of the screen you might see a garbled “illegal instruction” error.
When chosen from the Level Select, the game will crash.
Sonic and Tails are in different symmetrical designs on the end signpost
Chemical Plant Zone uses a purple-pink accent in the background instead of olive green; buildings are also much lower
Seesaws similar to that in the final Hill Top Zone can be seen in Emerald Hill’s object debug – An interesting connection because HTZ’s uses Emerald Hill’s art.
Green Hill Zone (Sonic 1) (cut) (playable)
Chemical Plant Zone (playable)
Labyrinth Zone (cut) (empty) (debate on prototype of Genocide City)
Hidden Palace Zone (cut) (playable)
Green Hill Zone (playable) (renamed to Emerald Hill Zone)
Hill Top Zone (playable but crashes due to the game trying to call Sonic 1’s Final Zone boss)
Note:All button input codes mirror those of the Japanese version of Sonic 1.
Level Select: At the title screen, press Up, Down, Down, Down, Down, Up, and Start.
Debug Mode: At the title screen, press C, C, Up, Down, Down, Down, Down, Up, then A + Start.
Level Select with Debug Mode: Activate the level select code, but don’t press Start. Instead, let the demo play, then when it returns to the title screen, press C, C, Up, Down, Down, Down, Down, Up, then A + Start. Select a level and hold A until it loads.
Debug Patchcode: FFFFFA:0001. This patchcode removes the need to enter a Debug code. The level select code can be used to debug in any level.
Two-player Mode: Highlight an Act in the level select screen and press B + Start.
Sonic 2 Beta – Simon Wai prototype
The Sonic the Hedgehog 2 “Simon Wai” prototype is a prototype build of Sonic the Hedgehog 2 for the Sega Mega Drive.
It is a relatively early build of the game, thought to have been created around the middle of 1992.
This particular prototype is named after Simon Wai, who found the ROM on a Chinese website and subsequently brought it to the attention of the Western Sonic the Hedgehog fan community.
It was the first prototype to be found of Sonic 2, and for many years was simply referred to as “Sonic 2 Beta”.
The Simon Wai prototype is more advanced than the earlier “Nick Arcade” prototype above, though is still very much incomplete.
Only four levels can be played during normal gameplay; Aquatic Ruin Zone, Chemical Plant Zone, Hill Top Zone and Emerald Hill Zone (in that order).
A further nine can be accessed through a level select code, though none of these levels can be finished, and three are entirely empty stages.
Instead of playing the 1-Up sound when Sonic gets 100 or 200 rings, the game plays a prototype version of the music from Death Egg Zone (Death Egg Zone plays no music). However, if Sonic breaks open a 1-Up monitor, the proper 1-Up sound will play.
Tails has no balancing sprites, instead he uses a tail-less slowly animated version of his waiting sprites.
The concept for a partner is still a work in progress as Tails can lose rings for the player when hit, just like in the Nick Arcade prototype.
Tails’ AI is much simpler: he simply copies the moves that Sonic makes, and makes no attempt to keep up with Sonic.
If Tails dies, he will come back on-screen still in his death sprite, and will spin in whatever direction Sonic is facing in as soon as he hits the ground. This is because Tails can’t fly yet.
Spin Dash is still a work in progress, as Sonic and Tails can only charge the Spin Dash once, and the sound for when Sonic spins in Sonic 1 is heard, as there is no sound effect for the Spin Dash.
The full Blue Sphere game is unlocked when Sonic & Knuckles is locked on.
Genocide City and Death Egg, although empty, use the Emerald Hill palette.
Final boss music for Death Egg is in the ROM and is exactly the same as the final’s.
Tails uses slightly different jumping and rolling sprites.
Sonic’s sprites use the same palette as the final, but are Sonic 1 style. There are also unused spinning sprites in the ROM.
There is a bug where Sonic’s pushing animations are used instead of his running animation.
Tails is only playable via 2 player mode.
Sonic may only pass the signpost.
Sonic and Tails both share the same life and ring counters.
Sonic and Tails still have to defeat the boss in Emerald Hill.
There is no countdown for Tails after Sonic passes the signpost.
If the 2P controller isn’t used, Tails’ AI will still follow and copy Sonic.
Even though the 2 player level music exists, 2 player mode’s playlist is not yet implemented and thus the levels play their single player music.
Every zone can be selected for 2 player mode in the level select, except for Chemical Plant Act 2, Neo Green Hill, and Hidden Palace (forcing the game to load levels with water in 2 player mode results in a crash). However, loading any zone other then Green Hill (Emerald Hill in the final), Dust Hill (Mystic Cave), and Casino Night will result in a very strange looking mess of glitchy art tiles, as well as Tails’ camera using very broken scroll data. This is due to 2 player mode’s levels requiring more data than the normal 1 player levels, which means that zones not set up for 2 player mode will use garbage data instead of the necessary 2 player data. This behavior is also in the final game. However, in the final release, these zones can only be played in 2 player through cheating or hacking.
The SEGA screen does not show up during boot because of altering; but it can be present after a demo but it is the same as the SEGA screen from Sonic 1.
Neo Green Hill Zone
This zone is only zone playable without Level Select cheat.
Actually, Aquatic Ruin Zone is named as Neo Green Hill Zone. Not to be confused with the Sonic Advance level of the same name.
There are no enemies except the arrow-shooting totems.
The layout is half-completed.
There is a corrupted splashing animation consisting of misaligned bubbles instead of a splashing sprite. Tails has no splashing effects.
If Sonic gets out of the water during the countdown, the music will be changed to the Emerald Hill theme.
Water does NOT have any effect on Tails other than palette change.
If you finish this zone, you will be sent to Chemical Plant Zone.
Chemical Plant Zone
As with Aquatic Ruin Zone, the Emerald Hill theme plays if you get out of the water during a countdown.
The loop-de-loop platforms have octagonal edges instead of being flat, just like the Nick Arcade prototype.
The platforms which move across rails (most noticeably in Act 2) are much smaller.
Demo gameplay hasn’t been rerecorded to fit new level design since the Nick Arcade build.
There is a badnik called Bubbler’s Mother that drops Bubbler that was set to appear in this zone. It can be seen through the method of hacking.
This zone has no Badniks in its level layout. As a result, Sonic can only be killed by getting crushed by the moving blocks (which don’t always crush properly), falling into a death pit, or by drowning.
Hill Top Zone
Sonic doesn’t spin when going through tunnels.
There is no earthquake sound effect.
The background music runs at a slightly slower tempo than in the final.
Demo gameplay hasn’t been rerecorded to fit new level design since the Nick Arcade build.
Green Hill Zone
In this Beta, Emerald Hill Zone is referred to as Green Hill Zone.
Demo gameplay for 2P Mode hasn’t been rerecorded to fit new level design since the Nick Arcade build.
Demo gameplay for 2P Mode illustrates a bug: both players share the ring counter (when one player gains or loses rings, so does the other). They also share the same lives counter.
There is a snail badnik that did not make it to the final ROM. Its art offset is at $7C514 (Nemesis compression, 26 blocks).
At one point, there is a hidden wall which is supposed to contain an extra life; it does but it is blocked off. The only way to get to it is by the use of Debug Mode.
This is the only zone with a boss. It looks exactly the same as it does in the final, but there are slight differences in its behavior:
The Eggpod drops straight down into the car rather than descending diagonally like the previous build.
When defeated, there are no explosion effects, unlike the previous build although it uses the explosions from Sonic 1. This proves that the explosions were taken out and the new ones from Sonic 2 final were added in somewhere in between this prototype and Sonic 2 Beta 4 during development.
If Robotnik was facing left, he will not turn around as he escapes to the right.
The boss does not turn as early as he does in Beta 4 and later: he goes all the way to the end of the road and back as opposed to halfway.
Pistons don’t throw you up as high as they do in the final.
Metal crushers do not hurt you unless you go underneath them when they come down.
Fire and lava have no effect.
Sonic falls through most of the rotating nets, but one of them does work (which suggests that the one working was the test object).
Sonic can rotate a nut upwards past the height of the supporting screw pole.
Act 3 has a diagonal lift that was cut from the final game.
There is a Fourth Act which is exactly the same as Act 3 except Sonic starts in a different spot. This can be accessed by hacking.
If you ride the platforms over the lava at the beginning of the act, when they go under the lava, so will you. They are also visible while under the lava.
Oil Ocean Zone
This zone plays different music from the final, which was later used in Casino Night Zone 2P mode, but the music for Oil Ocean can be played in the sound test. It’s number 90 and 91.
The sun scrolls with the background, and is non-animated.
Wooden balls are embedded in the ground, and can be activated by pressing a nearby switch. They will pop up and move to the left at a fixed speed. Sonic can stand on these balls while they travel. They were dropped as a gameplay element from the final, possibly because nobody could think of a good use for them, but the chambers and switches can be placed with debug mode in the final, and both have the same behavior as in the beta. Wooden balls were seen in prototype shots of Sonic the Hedgehog’s Green Hill Zone, and can be seen in this game’s debug mode, but they cannot be placed.
Two seahorse enemies are found within the prototype ROM through hacking.
An unused, shoot-and-flee octopus enemy is found within the prototype ROM through hacking.
The oil splashing animation is missing and oil slides have no effect on Sonic.
A pipe in the level’s background is sucking oil up instead of pouring it out.
Mystic Cave Zone
In this Beta, Mystic Cave Zone is referred to as Dust Hill Zone.
Because of the lack of objects, this level requires debug mode to completely explore the level.
Act 1 has a few odd platforming issues near the end. Other than that, layout wise, both acts are identical to their final counterpart.
It seems Act 1 was only used for object testing: Act 1 has a bunch of randomly placed objects at the beginning of the level, but once you get halfway through, the level is empty.
Act 2 is also devoid of objects.
The bridge object works in Act 1, but it uses a switch to open it instead of vines seen in later builds.
The robots don’t exist yet in this build.
The level also uses music similar to the final version.
Casino Night Zone
Drastic art changes when compared to the final: This zone has a pink card-suit-based scheme with sky blue floors. The tile layout is pretty similar to the final, but many level pieces are broken or missing, requiring Debug Mode to go deep into the level.
There are no objects in this zone.
The only two objects in the zone’s object debug list are a ring and a monitor.
There is a prototype of the Crawl badnik which can be seen by hacking the ROM, it remains as a lost sprite in the Final Sonic 2.
Many of the flipping tiles are missing or the outlines flash and the tiles remain stationary. With hacking, it is possible to implement the rotating tile, because they exist, albeit without its flipping format.
There are no Sonic, Miles or Casino Tiles. Instead, these are part of the layout tiles themselves.
There is a different sound for the bouncers that give points and disappear after three hits (that don’t yet exist).
The background of Act 2 uses foreground layout chunks, making it somewhat harder to play Act 2.
The red bumpers that give 10 points per hit do not exist. If the object, obj44, is placed in the level, it instead places a solid wall, similar to the one from GHZ. Thus proving even further that Sonic 2 Beta is a build off Sonic 1.
Neo Green Hill Zone (playable) (renamed to Aquatic Ruin Zone)
Chemical Plant Zone (playable) (incomplete)
Hill Top Zone (playable)
Green Hill Zone (playable) (renamed to Emerald Hill Zone)
Wood Zone (cut) (incomplete)
Metropolis Zone (playable) (incomplete)
Hidden Palace Zone (cut)
Oil Ocean Zone (incomplete)
Dust Hill Zone (incomplete) (renamed to Mystic Cave Zone)
Casino Night Zone (incomplete)
Genocide City Zone (empty) (cut)
Death Egg Zone (empty)
Special Stage (void)
Cheat codes are different in the Simon Wai prototype from the final Sonic 2. These codes can be accessed by inputting button sequences or by various other methods.
Zone Select: Enabled by default. Simply press A+Start on the title screen. You can also manually enable it by pressing Up Down Down Down Down Up then A+Start
Debug Mode: Press C C C C Up Down Down Down Down Up then A+Start on the title screen, then highlight a zone in the stage select and press and hold: A+Start
2 Player vs mode: Highlight a zone in the stage select and press: B+Start to play the level in 2-player split-screen mode. This does not work on levels with water in them.
Night mode: Highlight a zone in the stage select and press: C+Start.
Sonic 2 Beta – Beta 4
‘Sonic the Hedgehog 2 “Beta 4” is a prototype version of Sonic the Hedgehog 2 (16-bit). It is one of many internal prototypes released by drx during the February 23rd, 2008 proto release.
Beta 4 and the subsequent “beta 5”, “beta 6”, “beta 7” and “beta 8” are internal builds of the game, never intended to be seen by the general public in any form.
Only days separate the build dates of these prototypes, and all were created towards the end of the game’s development cycle, with significantly fewer differences from the earlier prototypes available online.
Beta 4 has a time stamp of 1992-09-18 16:26, meaning it was created just over two months before the final game’s release.
The “beta 4” name originates from Sega themselves, having presumably succeeded a “beta 1”, “2” and “3” in the days and weeks prior to beta 4’s release.
Confusingly this numbering scheme is not thought to include the older “Nick Arcade” and “Simon Wai” prototypes, which were produced many months before beta 4 (that is to say, these are not “beta 1” and “beta 2”, respectively).
Sega likely only used the term “beta” in the final few weeks of the game’s development, though outside of the company, the word is often used to describe prototypes at a range of development stages.
Level select is activated with A + Start, no code is required.
Debug is activated by holding A when selecting a level on the level select screen. It can also be activated by holding A when you die, no code is required.
Some of the zones that play after the Title Screen are still using the demos from the Nick Arcade/Simon Wai builds.
The title cards are implemented.
This build also features a severely limited debug mode. Item placement mode is not accessible, nor is Sonic invulnerable. The coordinate display functions are working, however. Item placement mode can be forced using patch codes, but debug remains limited as the player cannot move in item placement mode and items can be placed once.
The Spike damage behavior works the same way as it does in Sonic 1.
When Sonic dies, the camera follows him all the way to the bottom of the level.
Even with debug or level select off, you can still restart the game by pressing A when the game is paused.
Invincibility stars are different.
Screen doesn’t move up/down when you hold the Up or Down arrows.
The Special Stages are different in color and design from the Final Version. The “(x) rings to go!” message never activates, and is not active until Beta 7.
Emerald Hill Zone is listed as “Green Hill Zone” in the level select screen.
The slots in Casino Night Zone do not work.
There’s a different sound in Casino Night Zone when you go into the slots.
Boss music does not change in Wing Fortress Zone or Death Egg Zone.
The first cutscene in Wing Fortress Zone doesn’t have any sound effects.
The spiky platforms in the boss of Wing Fortress Zone gets destroyed if the laser touches them.
The Death Egg only takes 8 hits.
Metal Sonic comes down slower.
You can control Sonic after beating the Death Egg.
Wood Zone and Genocide City Zone have been removed from the level select screen.
Hidden Palace Zone is disabled in the level select.
Through hacking, Hidden Palace Zone can be accessed and it is a garbled mess just like in the final, but Badniks and object art are still intact. Though it uses its original object layout, it uses Hill Top Zone Act 2’s level layout for some reason.
When passing Death Egg Zone, no ending is shown. Instead, the game resets with no credits.
2 Player Mode
2P special stage, towards the end rings glow and side-stripes glow. This is the result of the end goal being loaded.
2P special stage. Cannot jump over other player. However, hitting a mine puts you in front.
The text for 2 Player VS Mode’s Special Stage after winning 1 round (Most Rings Wins!) is now Win Twice Win All! instead.
The Eggman monitor doesn’t work.
Tails’ icon is always listed as “Miles”
There are no invincibility stars
There is no one minute countdown displayed on the other player’s screen if the opposite player finishes.
In the fourth Special Stage, there are only 42 rings in the first section, yet 45 rings are required. Therefore, it is impossible to get the fourth Chaos Emerald, and consequently impossible to get Super Sonic without hacking.
When Tails drowns, Sonic will also drown.
The collision detection in Emerald Hill Zone and Aquatic Ruin Zone is a bit wonky.
One of the elevators in Casino Night Zone doesn’t work properly.
You can get stuck if you Spin Dash into a rock in Hill Top Zone.
Oil Ocean Zone has some background and collision detection issues.
Metropolis Zone Act 3 cannot be played without using Level Select. Completing Metropolis Zone Act 2 takes you to Sky Chase Zone.
The propellers from the Wing Fortress will hurt you in Sky Chase Zone.
You can run past Eggman in Death Egg Zone.
Sonic 2 Beta – Beta 5
Sonic the Hedgehog 2 Beta 5 for the Sega Mega Drive/Genesis was released by drx during the February 23rd, 2008 proto release. It is also known as S2BETA5.
This is the first version with the final title screen style (choice between 1 and 2 player); it’s also the last without an Options selection on it.
It uses the old Sonic 1 style level select with the same zone names as Beta 4, but the level select appears behind Sonic and Tails.
Sonic on the title screen turns black when you go into the level select.
The game has a different Title Screen from Beta 4, which is the same Title Screen from the final.
“Sonic and “Tails” In” (or Sonic and Miles, depending on territory)
As in Beta 4, debug mode is present, but in the debug counter only. You can’t turn into anything. It is not possible to transform into Super Sonic without hacking, even with all 7 Chaos Emeralds.
Sonic no longer dies if he touches spikes while invincible.
Hidden Palace is still missing, it’s still listed on the level select screen but selecting it does nothing.
In Level Select menu, the Sonic the Hedgehog 2 logo covers zone list.
The item placement in Aquatic Ruin Zone isn’t complete.
Metropolis Zone Act 1 does not have an end level panel, leaving it impossible to finish.
Wing Fortress Zone is different in the beginning, and contains a cheap death in which you are pushed off the starting platform. This is the last beta where it is different from the final.
In Death Egg Zone, it is possible to run completely past Robotnik’s mech before he gets in, debug not required. If you die, he’ll keep doing whatever it is he was doing.
In the ending (ending is available in this version) after Tails catches Sonic on the wing of the plane, they fly off to the right and then the game starts over.
In the Special Stage, the “Not Enough Rings…” sound is different from the final and remains that way through Beta 6; it was erroneously the “Cool!” sound in Beta 4. In the final, that sound is used in Casino Night Zone boss.
Some of Sonic’s sprites are different from the final game’s.
Sometimes, when performing a Spin Dash, Sonic will do it with the running animation.
A silly Chemical Plant Zone glitch related to the camera scrolling after death is in this beta.
In the boss arena of Oil Ocean Zone’s boss, the oil acts as a bottomless pit.
In Sky Chase Zone, stand on a turtle, and Sonic can scroll off screen if you wait.
When Tails gets hurt and lands in Sonic and Tails mode, he uses Sonic’s height properties.
Sonic 2 Beta – Beta 6
Sonic the Hedgehog 2 Beta 6 for the Sega Mega Drive/Genesis was released by drx during the February 23rd, 2008 proto release.
It is also known as S2BETA6. There seem to be two versions of Beta 6; but aside from a couple bytes in the header they’re identical, byte-for-byte.
Level Select code: Up, Down, Down, Down, Down, Up, highlight 1 player, then press A + Start.
Debug code: C, C, C, C, C, C, Up, Down, Down, Down, Down, Up, highlight 1 player, then press A + Start.
Level select is still similar to that of Sonic 1 in this build. The level select menu appears behind Sonic and Tails, and Sonic is all black. This is because, as JoseTB explained, “the first line [of the title screen palette] was the background in previous builds, but it’s used by sonic in the new title screen. Of course, the level select palette remained untouched with the change.”
Appears to be the first prototype with the options selection.
“Sonic and “Tails” in” (or “Sonic and Miles,” depending on region)
The special stages remain the same, except with a palette change.
As in Sonic the Hedgehog 2 (beta 4) and Sonic the Hedgehog 2 (beta 5), the player can run right past Robotnik in Death Egg.
The final boss only takes one hit, most likely to facilitate testing of the newly-programmed full ending. In previous builds, Sonic and Tails just fly off to the right.
Super Sonic’s ending is not implemented, Sonic’s regular ending is used instead.
Tails’ ending is not implemented; he uses Sonic’s.
The Sonic 1 style spike behavior has been changed.
The “You got a Chaos Emerald!” screen is glitchy.
The collision detection in Emerald Hill Zone is a bit wonky in some places.
If you complete Wing Fortress Zone as Super Sonic, you’ll end up jumping over Tails’ plane, and fall to your death.
When Super Sonic clears a level he will not go back to normal Sonic and the ring counter will still continue to drain until it hits zero.
If Sonic breaks an invincibility monitor and goes Super he will have the invincibility stars. This bug is also in the final.
Sonic 2 Beta – Beta 7
Sonic the Hedgehog 2 Beta 7 for the Sega Mega Drive/Genesis was released by drx during the February 23rd, 2008 proto release.
It is also known as S2BETA7.
Level Select code: Up, Down, Down, Down, Down, Up, highlight 1 player, then press A + Start.
Debug code: C, C, Up, Down, Down, Down, Down, Up, highlight 1 player, then press A + Start.
“Sonic and “Tails” in” appears instead of “Miles ‘Tails’ Prower.”
Sound does not stop when the game is paused.
Only Up and Down work at the level select.
Sound test option at level select is glitchy until highlighted.
“Option” instead of “Options”.
“Sonic only” and “Tails only” instead of xx alone.
No Hidden palace, no wood zone, similar to the final.
This is the first Sonic 2 prototype since Beta 4 where Debug works.
Robotnik’s final robot still starts in the center.
The laser sound effects that hit Tails’ plane are slightly different.
Boss music doesn’t play during Wing Fortress Zone boss.
When Sonic jumps onto the biplane at the end of Wing Fortress Zone, the jump sound plays twice.
In the Special Stage, the “(x) rings to go!” message is active; it was not in previous betas. However, even if you have 0 rings to go, the message stays on-screen until the “Cool!”/”Not Enough Rings…” message appears instead of disappearing as in the final.
Still contains the Tails megascore glitch.
When a level is clear with Super Sonic, Sonic doesn’t change back to normal Sonic and the ring counter still drains rings until it hits zero.
Sonic 2 Beta – Beta 8
Sonic the Hedgehog 2 Beta 8 for the Sega Mega Drive/Genesis was released by drx during the February 23rd, 2008 proto release.
It is also known as S2BETA8
Level select code is the same as in the final, and the new level select screen is done. The debug code from the final doesn’t work. The old codes also work.
Level Select code: Up, Down, Down, Down, Down, Up, highlight 1 player, then press A + Start. Using 19, 65, 9, 17 in the sound test works in this build as well.
Debug code: C, C, Up, Down, Down, Down, Down, Up, highlight 1 player, then press A + Start.
“Sonic and “Tails” in:” (or Sonic and Miles, depending on your region).
In Chemical Plant Zone Act 2, the huge shortcut with the three boxes that leads straight to the boss has two super rings and a life, while in the final it’s two super rings and an invincibility.
In Aquatic Ruin Zone Act 1, there is an invincibility monitor and a ring monitor on top of the first loop that are not present in the final.
Hidden Palace Zone is removed.
The boss of Wing Fortress Zone only takes one hit to defeat.
The final boss in Death Egg Zone is closer to the entrance in this build. Sonic does not run past Robotnik after defeating the Giant Mech, as in previous builds.
Ending sequence and credits are implemented.
Super Sonic doesn’t change back to normal Sonic when a level is clear, this causes the ring counter to still drain until it hits zero.
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I hope you enjoyed playing these ROMS
If you would like to download all of these ROMS to play for yourself offline, you can download them here. Remember you will need a Sega Mega Drive/Genesis emulator to run them
Please check out these pages for more Sonic related ROMS you can also play online.
Sonic Delta – A series of hacks that restores several deleted levels and prototype elements from Sonic 2.
Sonic Classic Heroes – Play through Sonic 1 & 2 as a team of Sonic, Tails and Knuckles (or alternatively as the Chaotix Crew team of Espio, Vector and Charmy)