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
30.75 million first-party Genesis units were sold worldwide. In addition, Tec Toy sold an estimated three million licensed variants in Brazil, Majesco projected it would sell 1.5 million licensed variants of the system in the United States, and much smaller numbers were sold by Samsung in South Korea. By the mid-2010s, licensed third-party Genesis rereleases were still being sold by AtGames in North America and Europe. Many games have been rereleased in compilations or on online services such as the Nintendo Virtual Console, Xbox Live Arcade, PlayStation Network, and Steam. The Genesis was succeeded in 1994 by the Sega Saturn.