From Sonic Retro
Sonic Jam (ソニック ジャム) is a 1997 Sega Saturn game. Primarily it is a compilation containing the four Sega Mega Drive Sonic platform games - Sonic the Hedgehog, Sonic the Hedgehog 2, Sonic the Hedgehog 3, and Sonic & Knuckles, however it also contains bonus content in the form of Sonic World and a number of different gameplay options.
Unlike later compilations, Sonic Jam does not emulate Mega Drive hardware - the games have been re-written for the Saturn, though behave almost identically to their original counterparts. It is especially benficial to PAL users, as the games have been optimised for 50Hz refresh rates (the original PAL versions perform 17.5% slower than their NTSC counterparts and contain borders, as little optimisation work was done between the two versions).
Each of the games benefit from the Lock-On technology introduced in the Sonic & Knuckles cartridge. This means Blue Sphere, Knuckles in Sonic 2 and Sonic 3 & Knuckles are also playable. The English and Japanese instruction manuals for each of the games are also included in a digitised form. The game also sports time attack modes, and an option to play each special stage in order for each game.
Customized versions of the games, with redesigned levels and varying levels of difficulty are included. When played in "Original" mode, the games are identical to their original Mega Drive 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 each level only 1 act long as well as adjusting the level design. Special stages are also easier in this mode. Sonic 1's Easy mode inspired a ROM Hack by LOst.
Another addition to Sonic Jam is "Sonic World", which is accessed at the title screen menu. A 3D adventure world with many buildings containing art, history, music, movies and character profiles is contained within, plus the mission mode where you must complete certain missions in the quickest time. At the time of Sonic Jam's release this game was a selling point as gamers were eager to see Sonic in 3D for the first time.
Sonic World is said to have been the basis for Sonic Adventure.
Differences from Mega Drive and Sonic Jam Versions
There are a number of changes between the Sonic Jam and Mega Drive versions of the included Sonic games, including enhanced sound and various bugfixes. Sonic the Hedgehog for example, adds an option to toggle the Spin Dash ability (which is absent from the Mega Drive release). The version of Sonic 1 used is based on the later revision of the game (not released in the west), and so sees extra scrolling with the clouds in Green Hill Zone and extra water effects in Labyrinth Zone. Also while Sonic halts to a stop while running, he leaves behind skid marks in Sonic 1, just like in later games.
Some of the audio in the game is different from the original Mega Drive versions, with most music tracks having a slight delay before playing (likely due to CD loading times). The version of Sonic 2 in this compilation uses the invincibility tune from the original Sonic the Hedgehog, presumably by accident as the Sonic 2 track in on the CD and used in the two player versus mode. Sonic 2's versus mode lags less often than in the Mega Drive version of the game.
However Sonic 3 and Sonic & Knuckles by far contain the most changes, though many are simply bugfixes. The sound effect for explosions (from monitors and enemies) is completely different, as are things such as collecting a blue sphere, or breaking a wall.
The game makes use of the Saturn's internal battery back-up as well as the Sega Saturn Back-Up Ram Cart to save data for all of the games as well as progress through the challenges in Sonic World.
Executive Producer: Hayao Nakayama
Music Composer: Masato Nakamura (©1992 Dreams Come True)
Original Sound Version Recordings
See Sonic Jam OSV for a download page.