Sonic Jam

Sonic Jam is a video game released for the Sega Saturn and Game.com. The Saturn version is a compilation of titles in the Sonic the Hedgehog series originally released on the Sega Mega Drive/Genesis. It was released in Japan on 20 June 1997, in North America on 31 July 1997 and in Europe during the month of August 1997.

Content
It includes the main Mega Drive/Genesis anthology (including Sonic & Knuckles and its lock-ons); Sonic Spinball and Sonic 3D Blast are not featured. The compilation also includes a 3D "Sonic World", which allows players to access virtual museums featuring Sonic the Hedgehog history, art, video game music and advertisements, as well as remastered and uncut animation sequences from Sonic CD. Sonic World functioned as both a hub for the extras and as its own game, utilizing missions such as ring-collecting, reaching markers, or finding Tails. Completing all the missions would unlock the credits for Sonic Jam.

Games included in this collection are:


 * Sonic the Hedgehog
 * Sonic the Hedgehog 2
 * Sonic the Hedgehog 3
 * Sonic & Knuckles

Furthermore, by selecting Sonic & Knuckles, the player can use the "lock-on technology" from its original cartridge version in order to link up to the other three games in the collection, making the following games also playable:


 * Sonic the Hedgehog 3 & Knuckles
 * Knuckles the Echidna in Sonic the Hedgehog 2
 * Blue Sphere

Sonic Jam also included customized versions of the games, with redesigned levels with varying levels of difficulty. When played in "Original" mode, the games are identical to their original Mega Drive/Genesis releases. "Normal" difficulty adds extra rings and alters other aspects of the design to remove some of the challenge (these versions of the levels are used when playing Sonic Jam 's Time Attack feature). "Easy" difficulty removes certain stages entirely, making the game much easier to complete.

Also implemented into Sonic Jam was the option to use Sonic's signature move, the Spin Dash, in Sonic the Hedgehog (on any of the above difficulties); originally, it did not debut until Sonic 2. There were also fixes of some glitches, particularly in Sonic 3. The games were not simply direct emulations like in later compilations, but rather elaborate ports to utilize the Saturn hardware.

According to the Sonic City website, Sonic World is a test level for what eventually became Sonic Adventure.

The Game.com version is completely different. Due to space limitations, Sonic 1 is not present, and each "game" consists of 4 levels based on the first level of the respective game (Emerald Hill, Angel Island, and Mushroom Hill). Sonic, Tails and Knuckles are playable for all games, and Tails can fly, but Knuckles can't glide or climb. Curiously, this version's box art features the same render found on that of Sonic R.

Changes
Some of the audio is presented slightly different than they originally were on their original system. This is due to the CD format. The version of Sonic 2 in this compilation uses the Invincibility tune from Sonic the Hedgehog, though the VS mode does use the original game's Invincibility. The speed-up music is also a separate track on the CD, so the game restarts the level music when that power-up is used. There are also some enhanced sound effects, particularly in Sonic 3 and Sonic & Knuckles where the sound effect for explosions (from monitors and enemies) is completely different. While the graphics are replicated perfectly on the Saturn, there is one additional visual effect in Sonic 1. While Sonic halts to a stop while running, he leaves behind skid marks just like in later games. This is actually not a brand new graphic. It is unused within the original game's ROM, but never implemented in the game. So far, Sonic Jam contains the only version of the original Sonic the Hedgehog where this lost graphic appears.

Some of the port implemention is imperfect, however. In some moments, slowdown does occur where it did not in the original games. If too many sound effects are going on at once, the sound may glitch up and sound unnatural. If the player crashes the game in debug mode of any game, the entire CD freezes as well. Finally, there are some additional graphical errors, most notably in Sonic 3 & Knuckles - if Knuckles manages to trigger Eggman as his opponent in Mushroom Hill Zone, the fought character will use both Eggman and EggRobo's sprites, making the boss a weird mash of both. Despite the discrepancies in the ports, Sonic Jam is still considered one of the best Sonic compilations due to its wealth of extras.

Trivia

 * This is the first Sonic game to be released on a non-Sega console.
 * The Game.com version is currently the only official, licensed Sonic game to be presented in monochrome, without color, because the Game.com does not have a color screen.
 * The Game.com version's cover artwork is of Sonic R 's cover art, rather than Sonic Jam's.
 * Interestingly, the Game.com version uses unused sprites from Sonic 3. These include Sonic falling asleep and whistling.
 * Knuckles can't glide in the Game.com version.
 * An infamous out-of-bounds glitch is present in Sonic World, where the player can find their way out of the stage and find endless land stretching in front of them.
 * This game consists of one of the few times the name "Eggman" appeared outside Japan before Sonic Adventure. (Conversely, it is the only time the original full name "Ivo Robotnik" appeared in Japan.)
 * All of the games in this compilation have been featured together again in later compilations, all of them were in Sonic Mega Collection and its PS2 remake, Sonic Mega Collection Plus, the games minus the Sonic and Knuckles add-ons were in Sonic's Ultimate Genesis Collection, and all of them except Blue Sphere were in Sonic Classic Collection.
 * The music that plays when you enter a virtual museum is used again in Sonic Generations and is itself a more mellow remix of the Sonic the Hedgehog 3 "File Select" theme.