Sonic the Hedgehog (16-bit) (prototype)

From Sonic Retro

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Sonic the Hedgehog (prototype)
Prerelease of: Sonic the Hedgehog
System: Sega Mega Drive
ROM size: 512 KB
Source: EPROM cartridge
Found by: Buckaroo[1]

The Sonic the Hedgehog prototype is a prototype build of Sonic the Hedgehog for the Sega Mega Drive.

This prototype build is very incomplete, with a number of incomplete Zones. Attempting to play the game normally, only the entirety of Green Hill Zone and Marble Zone, as well as the first Acts of Spring Yard Zone (Sparkling Zone) and Star Light Zone are playable. Most other levels in the game can only be accessed via the level select, and neither of them can be completed due to the lack of signposts and bosses, with Scrap Brain Zone (Clock Work Zone) Act 3 and Final Zone being nonexistent.

Among the Zones present in this prototype, there are many things that are different from the final build, such as different backgrounds, very different level layouts, and objects that would be deleted or dummied out. The existence of many of these differences has been known for years via early magazine scans and video footage, and their presence in this prototype reveals some insight on the game's development.


An EPROM cartridge of the prototype was found by Buckaroo, who dumped the cartridge to be released by drx of Hidden Palace. The prototype was streamed on Twitch on December 31, 2020, with the ROM being released on January 1, 2021.

By the end of January 2021, Buckaroo put the original cartridge up for auction on eBay with a starting price of £5,000, and was won by drx with a bid of £9,600 ($13,182.72 USD at the time) on January 31st, 2021.[2]


Sonic Retro emblem.svg Main article: Sonic the Hedgehog (16-bit) (prototype)/Comparisons

Physical scans


Download.svg Download Sonic the Hedgehog (16-bit) (prototype)
File: Sonic the Hedgehog (16-bit) (Prototype).zip (269 kB) (info)

External links


Sonic the Hedgehog (16-bit) (prototype), prototype version of Sonic the Hedgehog (16-bit)
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Main page | Comparisons | Maps | Hidden content

Part of Sonic the Hedgehog (16-bit) development

Sonic the Hedgehog (16-bit)
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Main page (Gen|2013|3D|Ages)
Comparisons (Gen) (2013)
Maps (2013)

Promotional material
Magazine articles (Gen)
Video coverage
Reception (Gen)

Hidden content (Gen) (2013)
Bugs (Gen)
Region coding
Hacking guide