Sonic the Hedgehog 2

Sonic 2 was developed simultaneously in Japan and America — Sonic Team in Tokyo and STI (Sega Technical Institute) in Palo Alto — in a pioneering transoceanic collaboration. Tails, the two-tailed fox, was introduced as a second player-controllable companion. The spin dash — standing rotation to launch at full speed — became Sonic's iconic move. Chemical Plant Zone is one of the most exhilarating levels ever: speed, transparent tubes and frenetic music. Golden Super Sonic was the reward for collecting all seven Chaos Emeralds in pseudo-3D special stages. Sold 6 million copies at 'Sonic mania's' peak.