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 Blast
The game was developed by Aspect Co. and published by Sega for the Game Gear. It was the final "Sonic the Hedgehog" game for the system, and has been rereleased on the Master System (1997), through two "Sonic"-themed compilations (2003 and 2004), and the Nintendo 3DS's Virtual Console (2012). Despite their similar titles and coinciding releases, "Sonic Blast" and "Sonic 3D Blast" have little in common. Retrospective reviewers generally had little praise for "Sonic Blast" and have deemed it one of the series' worst games. Although some considered its graphics impressive when considering the technological restrictions of the Game Gear, most found its animations and colors mediocre. The level designs and slow gameplay were also criticized.