Sonic Riders may not have been the most critically-lauded entry in the character's history, but it provided an interesting spin of the racing concept first introduced in Sonic R. However, according to Unseen 64, Riders could well have been inspired by pitch made by a North American studio called Vision Scape.

A prototype for a skateboarding game called Sonic Extreme surfaced recently and, according to Vision Scape's boss, was created in a week from an existing game engine. Vision Scape was working with Sega at the time on the CGI cut-scenes for Sonic Heroes, and began speculative work on the prototype when another project fell through.

The pitch got as far as Yuji Naka at Sega, who was apparently enthusiastic about the idea and seemed keen to move forward with with it, aiming for a release on GameCube, PS2 and Xbox. He requested that Vision Scape put together a design document and a proposed budget for the project, but then things went quiet. Vision Scape's repeated attempts to contact Sega and Naka were both met with silence and Sonic Extreme was forgotten.

Two years later, Sega released Sonic Riders, a game that was thematically similar to Sonic Extreme. Coincidence? Watch the video above and leave a comment to tell us what you think.