How Sonic the Hedgehog was conceived to help Sega compete against Nintendo in the early 90s was discussed during a postmortem for the original game at this year's Game Developer Conference.
Most of the talk was about Sonic's appearance came to be. Though the decision to make Sonic a hedgehog was seemingly a straightforward one - allowing him to deal damage by curling up into a ball and rolling around, designer Hirokazu Yasuhara explained - it actually wasn't Sega's only choice of character...