Sonic Chaos is a platform game for the Sega Master System developed by Aspect and published and released by Sega in Europe on October 25, 1993. It was later released for the Sega Game Gear in Japan on November 19, 1993 under the name Sonic & Tails (ソニック＆テイルス, Sonikku to Teirusu), on November 23, 1993 in North America under simply Sonic Chaos and in Europe in November 1993 under the same name.