During the early 1990s, Sega was one of the most successful video game companies due to the rise of its Genesis console. Genesis sales were driven by the popularity of Sega's flagship franchise of 2D platform games, Sonic the Hedgehog. During this time, series co-creator Yuji Naka worked with Sega Technical Institute (STI) in the United States to develop Sonic games. After the completion of Sonic & Knuckles in 1994, Naka returned to Japan to work with Sonic Team. STI began developing Sonic X-treme for the Sega Saturn, planned as the first Sonic the Hedgehog game to feature full 3D gameplay. X-treme suffered a series of setbacks and was canceled in 1996. The cancellation is an important factor in the Saturn's commercial failure, leaving it with no original Sonic platform game. Meanwhile, Naka and Sonic Team developed original Saturn games, such as Nights into Dreams (1996).
