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".
Sonic Gems Collection
"Sonic Gems Collection" is a compilation of obscure video games published by Sega for various consoles, such as the Sega CD, Sega Saturn, and Game Gear. It primarily focuses on "Sonic the Hedgehog" games, such as "Sonic CD" (1993) and "Sonic the Fighters" (1996). It also includes six of the twelve "Sonic" games released for the Game Gear. These games encompass various genres, such as platforming, fighting, pinball, and puzzle. Additionally, players can unlock several Sega Genesis games unrelated to "Sonic", including the two "Vectorman" games (1995 and 1996). Four games in the international version, "Bonanza Bros." (1990) and the "Streets of Rage" trilogy (1991—1994), are not included in the North American version. Each game is mostly identical to its initial release, but some were changed; for example, "Sonic R" runs at a higher frame rate.