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
The Sega Genesis, known as the in regions outside of North America, is a 16-bit home video game console developed and sold by Sega. The Genesis was Sega's third console and the successor to the Master System. Sega released the console as the Mega Drive in Japan in 1988, followed by North America as the Genesis in 1989. In 1990, the console was distributed as the Mega Drive by Virgin Mastertronic in Europe, Ozisoft in Australasia, and Tec Toy in Brazil. In South Korea, the systems were distributed by Samsung as the Super Gam*Boy and later the Super Aladdin Boy.