Mortal Kombat 4 is the fifth and final arcade game in the Mortal Kombat series of fighting video games. It was later ported to the PlayStation and Nintendo 64. An updated version titled Mortal Kombat Gold was released a year later exclusively for the Sega Dreamcast. It is one of the few 3D fighting games to have been described as having "2D gameplay."
As revealed in later interviews, programmer Ed Boon was particularly concerned with maintaining the gameplay feel of a 2D game but with 3D graphics. He at first was worried that there was some intrinsic property of 3D graphics that would make this impossible. Essentially, the major gameplay difference between 2D and 3D fighting games of the time, was that up to that point all 3D fighting games had attempted to somewhat simulate realistic martial arts. One of the reasons this was done was to take advantage of the fluid keyframed and motion captured animation that was now possible using 3D models. For example, in Virtua Fighter, a real martial artist was filmed performing the moves, and this movement was imposed on the 3D model in the game. Thus, while a punch in a 2D game might be a rapidly responding move with two frames of animation, a punch in a 3D game might have a delay between when the button was pressed and when the opponent was hit, owing to the realistic animation.
This delay however fundamentally changed the gameplay experience. Boon eventually decided to use the non realistic 2D rates of animation and movement, simply imposed onto 3D graphics. Thus the gameplay experience is nearly identical to the 2D versions of Mortal Kombat. While this was attempted before with the Street Fighter EX series, that series used more complex animation which did change the gameplay somewhat. Some critics however, were disappointed that Mortal Kombat 4 did not play like other popular 3D games of the time.
MK4 also included the following hidden characters:
Quan Chi poses as the final boss when Shinnok is used by the player. Also, Shinnok appears as both the boss and sub-boss character when playing as Goro.
Thousands of years ago, during a war with the corrupt Elder God known as Shinnok, Raiden was responsible for the death of an entire civilization. To avoid a repeat of this event, as well as to protect all realms from Shinnok's threat, Raiden waged a brutal campaign and, at a heavy price, exiled his rival to a dark place known as the Netherealm. A couple of years before the Shaolin tournament, the original Sub-Zero assisted the necromancer Quan Chi in obtaining Shinnok's amulet, the source of Shinnok's power to traverse the realms (as recounted in Mortal Kombat Mythologies: Sub-Zero). Now, after Shao Kahn's failed attempt to seize Earthrealm, Quan Chi has allied himself with Shinnok and helped the god escape from his confines. With the help of an Edenian traitor, they enter the Heavens and kill most of the gods, but Fujin and Raiden escape and gather Earthrealm's finest warriors to fight them. The Raiden-Shinnok feud had burst open once again, but this time the battle could be won by mortals.
The Dreamcast version, titled Mortal Kombat Gold, was released on September 9, 1999 as a launch title for the console in North America. The game retains the character roster from the previous versions of Mortal Kombat 4, along with six additional characters from previous Mortal Kombat games. These additional characters were Kitana, Mileena, Cyrax, Kung Lao, Baraka, and one secret character, Sektor. Gold also includes new levels not seen in Mortal Kombat 4 and a new weapon select mechanism.
A new character named Belokk was intended to appear in the game, but was cut from the released game. The developer of the game, Eurocom, sent information about the game with Belokk in it to Game Informer, and as a result, six screenshots of him were published. According to Ed Boon, Belokk was cut due to time constraints during development.
Mortal Kombat Gold did not receive high marks for visual quality even though its character models for the fighters themselves were of higher quality than those seen in the home console ports of MK4. Game Revolution commented, "The graphics are inexcusably horrible [and] it's quite a depressing let-down on Sega's 128-bit masterpiece, especially when compared to Soul Calibur." The weapons that characters can use during the game are "dull and uninteresting," often have little relation to the characters, and are "either a sword, axe, or club."
IGN had similar bad reviews about Mortal Kombat Gold, particularly regarding the poor weaponry: "[R]eadying your weapon is a slow process in which one can be hit any number of times during the attempt." Although they commented on the improvements from previous Mortal Kombat games, the lack of depth was considered somewhat inexcusable. In other ways, due to loading times (even during battles, particularly in the case of Shinnok's impersonations) and glitch-laden effects, its quality was actually poorer.
A second revision of the game, known as version 2.0, was released about a month after the initial release intending to address some of the major issues in it. This version fixed the most severe bugs and glitches in the game and added VMU support, which allowed saving to work properly. The revision is identifiable by a red tinted disc, as opposed to the original's gold tint, and a green sticker saying "Hot! New!" placed on the instruction manual cover.