Sonic the Hedgehog: The Movie was going to be a film in 2002, based on the Sonic SatAM TV Show and the Archie Comics, possibly made around the time of Sonic's 10th Anniversary.
Development and History
The late Ben Hurst, one of the writers for Sonic the Hedgehog, attempted to pitch a movie in an attempt to revive the old Saturday Morning universe, shortly after MGM gave the film rights for Sonic the Hedgehog back to Sega. However, it's said that Ken Penders, then-head writer of Archie Comics' Sonic the Hedgehog, got wind of this attempt and, after initially working with Ben, apparently killed his attempt by claiming to Sega that he was trying to co-opt the franchise. To add insult to injury, Penders then brought up his own concept for a movie There are four concept pieces for the movie. The movie seems to work in the idea that Mobius would have been destroyed and that roboticization would be a much more gruesome procedure than was shown in the cartoons and comics. A number of major characters are not shown and a few of them have major redesigns (the biggest being Snively, who's now more cyborg-like). There was some interest, but at the time Sonic X was being made and they felt it wouldn't be worthwhile to have two running series in two different continuities, so it was backburnered, then dropped completely. With the subsequent announcement of a live-action/CGI Sonic in the works at Sony Pictures a decade later, it's safe to say that any chance of the comics-based scripts being green-lit is dead.
Concept Art
The Moment where Modius was destroyed
Snively, (who's now more cyborg-like) proseding in Roboticization (which would be a much more gruesome procedure).
All the Characters even sonic's possible sister