In 1991, Sega released the first Sonic the Hedgehog game into the UK. (I remember it well, I used to get excited when I visited my aunt's because my cousin had it). It, in turn, spawned many more sequels:
Sonic 2 (originally named)
Sonic 3 (again, originally named)
Dr Robotnik's Mean Bean Machine
Sonic C.D.
Sonic and Knuckles
Sonic 3D
As well as the above games, there were also a few that were never released in this country:
Sonic Drift (only released in Japan)
Sonic Crackers (Sonic 4, but was replaced by Knuckles Chaotix, so it was never released)
Following the success of the games, numerous cartoons and comics were broadcast and sold in the shops. These included:
Sonic the hedgehog (With Sally, Bunnie, Dulcy etc, as permanent characters)
Sonic the hedgehog (With just Sonic and Tails
Sonic Underground (With Sonic and his siblings, Sonya and Manic)
S.T.C. (Sonic The Comic, I have hundreds of these in my closet!)
And it didn't end there! Pretty soon Dreamcast had been released, and with it Sonic Adventure. However, it didn't last! Sega Dreamcast never quite took off and production of these consoles ceased! Sonic now appears on Gamecube with his evil shadow, named.... well.... Shadow of course!
The Hedgehog himself tends to change his personality depending on the cartoon or comic, but no matter what he appears in, he's always the cool, blue, speedy, spikeball with attitude.
