Sonic Team
The initial team formed in 1990 and was composed of developers from Sega's Consumer Development division, including programmer Yuji Naka, artist Naoto Ohshima, and level designer Hirokazu Yasuhara. The team took the name Sonic Team in 1991 with the release of "Sonic the Hedgehog" for the Sega Genesis. The game was a major success that contributed to millions of Genesis sales. The next "Sonic" games were developed by Naka and Yasuhara in America at Sega Technical Institute, while Ohshima worked on "Sonic CD" in Japan. Naka returned to Japan in late 1994 to become the head of CS3, later renamed R&D #8. During this time, the division took on the Sonic Team brand but developed games that do not feature Sonic, such as "Nights into Dreams" (1996) and "Burning Rangers" (1998).
Knuckles' Chaotix
Development of "Knuckles' Chaotix" began in early 1994 as an engine test for the Sega Genesis dubbed "Sonic Crackers". Although Sonic Team is sometimes credited for developing the game, it was developed by another internal Sega development team including young members of the staff who had worked on "Sonic CD" (1993). Developed as an idea for the next "Sonic" game, the prototype featured Sonic and Tails joined together by an elastic band of energy. Development eventually moved to the more powerful 32X add-on for the Genesis. Sonic and Tails were replaced by a group of characters led by Knuckles the Echidna, but the core tethering gameplay was retained. The project was titled "Knuckles' Ringstar", and later "Knuckles' Chaotix". The "Sonic Crackers" prototype ROM image was later leaked online and can be played with emulators.