This article pertains to the beta elements from SegaSonic the Hedgehog.
The prototype of the arcade game exists as the "Revision A" version. There are numerous differences, most of which feature different level layouts, gimmicks and alternative level order. Differences included:
- The title screen for this version is white and without a moving background. The logo also only shows Sonic posing and does not feature Mighty and Ray.
- There are no character select screen in this version, as the player automatically starts with three playable characters.
- This pre-release version only has four playable levels, some of which have not been given final names. These include Volcanic Vault which is unnamed, Icy Isle which is called "Ice World", and Desert Dodge which is called "Desert Zone".
- The level order is different. Icy Isle is the 4th level, Desert Dodge is the 5th level, Trap Tower is the 2nd level and Landslide Limbo is the is 3rd level. In the final game, Icy Isle is the second level, Desert Dodge is the third level, Trap Tower is the fourth level and Landslide Limbo is the fifth level.
- When the player accesses the quicksand section in Desert Dodge, the ability to continue will be taken away.
- After completing Desert Dodge, the game ends with a "TO BE CONTINUED" and instant Game Over screen.
Early title screen poses
One of prototypes has the animations of Mighty and Ray appearing on the title screen, but they are not seen in-game; the final version updates them with idle animations and adds highlights to their eyes. Sonic's head was also redrawn for his finger-wagging animation, and Mighty has two copies of his title screen sprites, the latter having more highlights for his nose.
Early character select sprites
Two alternate sprites from the character select screen exist in the graphic data. Sonic's early sprite is more deflated compared to one used in the final game, while Ray's patagia were emphasized in the final game.
Early intro cutscene sprites
There are two sets of each of the characters' intro sprites, mostly of which feature minor shading differences. Sonic's arms are animated differently, Ray is resized and his and Mighty's faces were adjusted. Mighty is the only one whose early sprites has the "panic" expression, which is different from how they are portrayed in the final game.
Flexing their muscles
There are animations of the playable characters flexing their muscles. The purpose for these sprites is unknown.
Unused Eggman sprites
While the player only encounters Dr. Eggman at the end of Eggman's Tower in the final game, there are unused sprites that suggest the doctor was originally going to be more involved in the levels by using holograms for encounters, remote controls and a bomb-throwing Egg Mobile.
There are leftover sprites of a debug menu, possibly for a level or graphic editor.
Unused dialogue bars
One of prototypes contain extra amount of dialogue bars with a dialoge between Sonic and Dr. Eggman. Sonic himself never talks through word balloons in the final game, so its color is otherwise unseen. Eggman talks about his "Almighty Tower" or "Tower of Omnipotence" (全能の塔). Otherwise, it is just basic trash talk.
Alternate Game Over sprite
Unused "insert more coin(s)" bars
There are two unused bars stating "Insert more coin(s)" for Sonic and Ray which are never displayed in the final game. They could have been intended for when players had to insert multiple coins per one credit. Also, an additional bar for Mighty never shows in the attract mode HUD, as his palette is estimated.
English-translated dialogue bars
Inside the final game's graphics data, there are dialogue bars translated into English. The game had a limited release in English territories, but none of these dialogue bars were used. There are also separate dialogue bars that show that the name for Eggman Island was intended to be translated into "Robotnik's island" or "Eggman's island".
Robotnik from Saturday morning cartoon
Inside the final game's code, there are alternative sprites that resemble Dr. Robotnik from Sonic the Hedgehog animated series, or Dr. Robotnik from the Sonic the Hedgehog comic series and its spin-offs (judging by Robotnik's color scheme). Much like the unused English dialogue bars, these sprites may have been intended to replace the original Eggman sprites for limited releases of the game in English territories. For full sprite sheet with unused sprites,