Game @-@ package illustrator Akira Watanabe said that his goal was to make the characters " colorful " , using clear lines and gradation to " finish them neatly " . According to Watanabe , the developers asked him to create a package design " similar to pop art ... without being particular to conventional packages " – something " original " and " stylish " . The game was released in North America , Europe , and Australia on June 23 , 1991 , and in Japan on July 26 . Sega of America packaged it with American Genesis consoles , replacing Altered Beast . Genesis owners who bought their consoles before the switch could request free copies of Sonic the Hedgehog by mail . Sega of America created a large @-@ scale marketing campaign to promote the game and Sonic as a mascot for the company .