This article pertains to the beta elements of Sonic the Hedgehog (1991).
In the title screen there was a "Press Start Button" text on-screen. The level select shows the original order of the zones placed, with some Xs listed after some levels, Final Zone is not listed in it. The "Press Start Button" text is visible once again.
Green Hill Zone
The first glimpse of Sonic the Hedgehog in video game form was at the Tokyo Toy Show in June 1990, which also happened to be the first time the game could be played by the general public. In a retrospective interview with Yuji Naka, it was revealed that the original Sonic Team put together a small, playable technical demo for the show featuring Sonic in an early version of the Green Hill Zone. Of note is that in the interview, Naka claims that this tech demo was planned at one stage to be included in Sonic Mega Collection, but was never in any build as the ROM has since been lost internally at Sega.
Green Hill Zone was initially different; the sky was darker than in the actual Zone, the conical mountains were normal mountains (they appear to be close in the background unlike the final version of Green Hill Zone) with few small waterfalls and no river to be found, and the clouds are bigger. There was a signboard giving the welcome to Sonic, in which it is thought to say: "You Are Welcome Sega, Sonic", with a picture of a palm tree in the top right hand corner. The rocks were originally orange; they were not a layout obstacle but instead found in the foreground along with the palm trees being independent from the clouds and other objects in the background, all separate from the scrolling of Sonic as he ran through the hill-like terrain, similar to those light posts from Star Light Zone.
In the second beta iteration of Green Hill, elements such as the taller purple flowers and the strikingly close water/sky shades of blue in this build did make their way in the finished version. The layout was different; the Ball Hogs were present in the level, along with the Robotnik monitor that later debuted in Sonic the Hedgehog 2. There was a rolling ball in which the player could move by pushing it, which was later used for the Egg Mobile-H boss fight. The differences are less evident, though the Debug Mode is present. This version was in the Consumer Electronics Show March 1991.
In Labyrinth Zone, the background was dark rocky with ceiling crystals (similar to this Zone in the 8-bit version), the crystals were a bit smaller. Due to at that point was in development, there are some sections empty with no water, and Act 3 had a completely black background.
Labyrinth Zone was going to be the second zone, according to the unaltered Level Select menu, but due to its high difficulty compared with the earlier stages, it was put as the fourth zone in the final version.
The background of Marble Zone originally had different ruins and floating platforms in the sky. UFOs are also in the sky, although in a different build. These can be placed via debug mode in the 2013 remake At first, there were no torches present in the background when inside the ruins.
Horizontal counterparts of the the spiked crushers were also found in some prototypes. These can also be placed via debug mode in the 2013 remake. Spikes, who is in Spring Yard Zone in the final version, was intended to appear in Marble Zone.
Marble Zone was going to be the third zone, according to the unaltered Level Select Menu, but was put as the second zone in the final version.
Star Light Zone
In the data for Star Light Zone, there are unused flashing lights.
"Sparkling Zone" is an early version of what would later be known as Spring Yard Zone. It had a starry sky background and more of a focus on neon lights and signs with text. It was originally going to be the second to last zone in the game.
Clock Work Zone
"Clock Work Zone" is known as Scrap Brain Zone in the final version and originally had a different background and other changes. The Zone is sometimes called "Clock Ork", as the game itself does not have a "W" in its title code.
|Robotnik monitor||Does nothing. This monitor was likely intended to hurt the player, as it does in Sonic the Hedgehog 2. It appears to be located in the second beta from Green Hill Zone.|
|Goggles monitor||This monitor was most likely accompanied by the unused goggle graphics, replacing the Air Bubbles. It was going to appear in Labyrinth Zone. Due to the programmers thought that the air bubbles gives Sonic some sort of weakness, the goggles were removed.|
|Static monitor||Does nothing. This monitor can be found in some parts of Scrap Brain Zone and can be broken by clipping through the walls. This is shown in Debug Mode when chosen a monitor in place, just before you step a monitor while Sonic 2 uses the Teleport monitors|
|S monitor||Does nothing. This monitor also appears in Sonic the Hedgehog CD prototype 510, where it grants the player extra speed and invincibility. This is most likely the intended function of the monitor here, as a Computer & Video Games issue alludes to a powerup which grants extra speed and invincibility. A similar version exists in Sonic the Hedgehog 3 & Knuckles which grants the user his Super State.|
Special Stage icons
Note: All of these items can be seen in-game by using the Debug Mode to fall outside the playing area of the Special Stage. It is easier to see them when advancing frame-by-frame by pausing and pressing C.
|"Zone" Icons||Found in the object list for the Special Stages with their graphics in the ROM. They are labeled as Zones 1-6, and are solid, like normal blocks, and were likely intended to show which Special Stage the player was in.|
|"1-up" Icon||An extra-life icon for the Special Stages. It is listed in the manual for the game, but it never actually appears. It is, however, fully functional, and can be placed in any special stage. The icon disappears when touched, like a ring.|
|"W" Icon||An icon with the letter W on it. Its use is unknown, and it has no function when placed in-game. It is solid, like a normal block.|
|Green Hill Zone||A checkered ball, first seen in early screenshots, and is later made part of the Green Hill Zone boss at the end of the level. It would have originally been its own object, chasing Sonic, and could crash through walls that he could not break through. The object can still be viewed with debug mode, but it cannot be placed by any means. It was restored in the 2013 remake, but it is pushed by Sonic there instead of it chasing him.|
|Green Hill Zone||Two faces, early versions of the Green Hill Zone decorations. They can be also seen in the Nick Arcade prototype of Sonic the Hedgehog 2 of Green Hill Zone on the glitched Crabmeats and the Act 3 boss. They are loaded naturally into the RAM addresses of, "FFBAC8" and "FFBAD0". A layer, in front of the sprites, can also be added on Green Hill Zone with these codes, "FF5970:0159" (happy face) and "FF5972:015A" (sad face).|
|Green Hill Zone||Unused tiles from Green Hill Zone but were used for the underground segment of Green Hill Zone's second act in the 8-bit version. These tiles later reappeared in Sonic Mania.|
|Marble Zone||A horizontally-oriented spiked chandelier object. It is fully functional but still goes unused. Can be added using patch code FFD004:4500 with Debug Mode active.|
|Spring Yard Zone||An unused sign present in Spring Yard's tileset, seen only in concept artwork.|
|Labyrinth Zone||A Burrobot facing downwards. Its purpose is unknown.|
|Star Light Zone||Unused lights from Star Light Zone.|
|N/A||Unused pieces of a capsule. They are loaded into the data of Robotnik's capsule, and the concept artwork shows extra gadgets attached to it.|
|Final Zone||This sprite shows the back parts of the legs of Robotnik's vehicle, which cannot be seen in the final version of the game.|
|Ending||A rosebud with an incorrect palette that functions like a bumper. This is because both the ending and Special Stage use the same debug item list, resulting in a strange-looking bumper due to the different art being used.|
|N/A||A block that uses the same color palette as Sonic. This can be found in tile graphics 2F66E-2F6B6 compressed in the Nemesis format. Its purpose is unknown.|
|"PRESS START BUTTON"||Text that was meant to appear on the title screen, but was disabled due to a programming error. However, it does appear on the Mega Drive systems, after viewing the invisible credits. It can be reactivated by using the code FFD11A:0100.|
|Splats||An unused Badnik that was cut late from the final game late in development. Several merchandise and media based on it were released as a testament to this. It later makes a proper appearance in Sonic Mania, as well as a cameo appearance.|
|Unused Explosion||An unused explosion, found along with Badnik artwork. This sprite matches the mappings of unused Buzz Bomber missile explosions.|
|Unused grass||A chunk of red grass. Its purpose is unknown. Early concept artwork shows a mechanic, where the grass would be differently colored, to show the location of hidden spike traps. It does not seem to match with any palette in the game.|
|Unused switch||An unused frame of the switch sprite. When bit 5 of a switch's subtype is set, it makes the object flash, using this sprite. In Labyrinth Zone, this sprite's data is partially overwritten by the cork sprite in VRAM. Marble Zone's switch has no equivalent sprite.|
|Title card period||A period intended for the title cards. It was seen in the pre-release version of the game.|
Unused Sonic sprites
|This sprite shows Sonic standing while gasping for air. This was presumably intended to be used in Labyrinth Zone.|
|This animation shows Sonic holding his breath while running. This may have been used during the countdown to signify Sonic is running out of air.|
|This unused sliding sprite is similar to the one used in Sonic the Hedgehog CD's Wacky Workbench.|
|As seen in a couple of prototype screenshots in magazines, Sonic appears to be striking a victory pose after passing the signpost. This sprite made its way into Sonic Mania.|
|These sprites, reminiscent of the Spin Dash, are present in the final ROM, but their use is unknown. Some theories are that they were used for a move similar to the Spin Dash or that they were intended for some sort of warp movement, perhaps through winding tunnels. It's also possible that a teleporter (like the one found in the 8-bit version of Scrap Brain Zone) would have played the animation.|
|This set of sprites showing Sonic shrinking are not used in the game. While their intended use is unknown, they could have been used to simulate the death animation for falling. They may have also been used for a "speed tunnel" that would extend into the background. Interestingly enough, a slightly modified version of the first sprite ended up being used in Sonic Eraser.|
|An unused black and white death sprite. This also exists, and is still unused, from Sonic the Hedgehog 2 and the v0.02 prototype of Sonic the Hedgehog CD.|
|These unused set of sprites shows the use of a type of goggle power-up. It is unknown what the power-up would have done but it is likely they would have allowed Sonic to breathe underwater. Sources of this were found in the ROM data of the game and was added as an extra debug monitor in the iOS remake.|
Unused warping effect
This effect happens when Sonic runs into an object placed somewhere in the act, causing him to disappear in a flash. It's purpose is likely unknown.
Original Egg Mobile-H design
Unused Egg Mobile explosion sprites
Unused sprites that show the Egg Mobile exploding. Their purpose is unknown.
- The idea of the welcome signpost was reused later in Casino Paradise Zone of Sonic Advance.
- The purple flowers make an appearance in Green Hill in the final moments of the game after the player has fought the final boss, while the similar shades of blue in the sky and water appear in the title screen.
- Originally, the 1-Up could be obtained by collecting 50 rings instead of 100. This can be seen during the North American commercial for the game.
Green Hill Zone
Spring Yard/Sparkling Zone
Scrap Brain/Clock Work Zone