Hidden Palace and The Cutting Room Floor have, with a little help, got hold of what must be one of the most interesting unreleased video games of all time: an early preview build of Sonic 3 that’s quite different from the Genesis game that was eventually released.
As Hidden Palace remind us in their report of the find, Sonic 3 had one hell of a struggle in development, originally beginning life as an isometric 3D game before reverting to its more classic 2D form in order to hit marketing deadlines. Then, when it was unable to hit those, it ended being split into two games (the second of which would go on to become Sonic & Knuckles).
The resulting mess not only meant Sega had to get outside help in order to get the game ready in time—especially when it came to the music—but that Sonic 3 in this earlier state wasn’t really shown to the media, neither at events or via preview code.
With one execption! Britain’s Sega Magazine was sent a copy for coverage, and that’s the code that has been tracked down now. It’s full of interesting changes from the game that we got in 1994, including the presence of a move that never made it into the final build (a “drop dash”), different music and even different level layouts.
The preview code has been made available for download if you want to try it out in an emulator, and you can get it here.