Sonic Jam
"Sonic Jam" is a compilation which contains the four main "Sonic the Hedgehog" games released on the Sega Genesis: "Sonic the Hedgehog", "Sonic the Hedgehog 2", "Sonic the Hedgehog 3", and "Sonic & Knuckles". Unlike future "Sonic" collections, "Sonic Jam" does not use a Genesis emulator; the games are proper ports, and all are nearly identical to the original Sega Genesis releases, with the exception of minor bug fixes. "Sonic Jam" emulates "Sonic & Knuckles" "lock-on technology"—a special feature that allows the player to merge elements of "Sonic & Knuckles" into previous games, resulting in changes to the level design as well as the choice to play as Knuckles the Echidna in "Sonic the Hedgehog 2" and Tails in "Sonic & Knuckles".
Sega Genesis
In mid-1990, Nakayama hired Tom Kalinske to replace Katz as CEO of Sega of America. Although Kalinske initially knew little about the video game market, he surrounded himself with industry-savvy advisors. A believer in the razor and blades business model, he developed a four-point plan: cut the price of the console, create a U.S.-based team to develop games targeted at the American market, continue and expand the aggressive advertising campaigns, and replace the bundled game "Altered Beast" with a new game, "Sonic the Hedgehog". The Japanese board of directors initially disapproved of the plan, but all four points were approved by Nakayama, who told Kalinske, "I hired you to make the decisions for Europe and the Americas, so go ahead and do it." Magazines praised "Sonic" as one of the greatest games yet made, and Sega's console finally took off as customers who had been waiting for the release of the international version of Nintendo's Super Famicom—the Super Nintendo Entertainment System or SNES—decided to purchase a Genesis instead. Nintendo's console debuted against an established competitor, while NEC's TurboGrafx-16 failed to gain traction, and NEC soon pulled out of the market. In large part due to the popularity of "Sonic the Hedgehog", the Sega Genesis outsold the SNES in the United States nearly two to one during the 1991 holiday season. This success led to Sega having control of 65% of the 16-bit console market in January 1992, making it the first time Nintendo was not the console leader since December 1985.