Sonic is one of the world's best-known video game characters and a gaming icon. Sonic was redesigned by Yuji Uekawa for Sonic Adventure (1998), with a more mature look designed to appeal to older players. The original Sonic the Hedgehog (1991) was released to provide Sega with a mascot to rival Nintendo's flagship character Mario. Most of the games are developed by Sonic Team. Programmer Yuji Naka and artist Naoto Ohshima are generally credited with creating Sonic. In most games, Sonic must race through levels, collecting power-up rings and avoiding obstacles and enemies. Sonic is a blue anthropomorphic hedgehog who can run at supersonic speeds and curl into a ball, primarily to attack enemies. Sonic the Hedgehog is the title character and the protagonist of the Sonic the Hedgehog video game series published by Sega, as well as numerous spin-off comics, animations, and other media.