Sonic and Mario

April 1, 2007: Back in the day when Sega and Nintendo were bitter rivals, no one would have thought that their hit characters Sonic the Hedgehog and Mario would team up in a game. But that's exactly what happened when “Sonic and Mario at the Olympics” was announced in 2007. Sega and Nintendo announced it via a joint press release a couple of days prior to April 1, but fans just assumed there was no way it could be true. Soon after, Sega stated on their official website that the game is official and that both Sega and Nintendo are working on this game project.