For the first time, certain levels were interactive by allowing characters to be uppercutted through the ceiling where both characters would continue the battle in a different stage. This could alter the game's level cycle. Both normal uppercuts and uppercuts that are part of a ground combo would result in a level change. Kung Lao's "Whirl Wind Spin" move would also have the same effect. However, if the final hit of a round happens to be an uppercut (i.e., the character is defeated by an uppercut), there is no level change.
All of the different style of finishing moves featured in Mortal Kombat II (Fatalities, Babalities, and Friendships) return in MK3. Additionally, the long rumored Animality, where the character transforms into an animal in order to kill their opponent, is featured for the first time. Another new addition is the Mercy, where the character can give their opponent a small sliver of life if they have won two rounds and are at the "Finish Him/Her" screen. It is necessary that a Mercy is performed for an Animality to occur. Finally, three new stage Fatalities can be performed in the Subway, the Bell Tower, and the Pit 3.
Another concept exclusive to this game are the "Kombat Kodes". These were 6 digit codes entered at the VS screen in a two player game to modify gameplay, fight hidden characters or display certain text messages. Also introduced in this game was the "Ultimate Kombat Kode", using a 10 character code using symbols, that could be entered after a game was over in single player mode. If the correct code was entered, Smoke would become a permanent playable character on the character select screen. The arcade owner, however, could reset this code by accessing the game's diagnostic menu by hitting a DIP switch within the MK3 cabinet.
The game's overall style was envisioned differently than in the previous Mortal Kombat games. Opposed to the heavily Oriental themes of Mortal Kombat and Mortal Kombat II, MK3's theme is much more Western contemporary. The game's stages are set in modern locations, three of the characters are cyborgs, and traditional character designs (such as Sub-Zero's or Kano's) have been dropped or modified in favour of modern replacements. The overall game has a much darker tone than its predecessors, and uses a noticeable darker and less vibrant colour palette. Characters are now heavily digitized (as opposed to the hybrid digitized/hand-drawn style of Mortal Kombat II.) Many of the game's backgrounds are now, for the first time, created using pre-rendered 3D graphics. This change is also reflected in the sound track, in which all Oriental motifs have been dropped in favour of modern instrumentation.
When Sindel is reincarnated in Earthrealm, Shao Kahn reaches across the dimensions to reclaim her. As a consequence of his action, the Earthrealm becomes a part of the Outworld, instantly stripping billions of their souls. Only a few are spared, as Raiden protects their souls. He tells them that Shao Kahn must be stopped, but he cannot interfere; due to his status, he has no power in Outworld, and Earthrealm is partially merged with Outworld.
Shao Kahn has unleashed extermination squads to roam throughout the Earthrealm and kill any survivors. Also, Raiden's protection only extends to the soul, not to the body, so his chosen warriors have to fight the extermination squads and repel Shao Kahn. Eventually with his final defeat, every human on Earthrealm comes back.
Mortal Kombat 3 follows Mortal Kombat II and shares continuity with both Ultimate Mortal Kombat 3 and Mortal Kombat Trilogy which were both updates of this game. The next new game in the series was Mortal Kombat 4.
Some of the returning characters from the previous games in Mortal Kombat 3 were actually portrayed by new actors, since their original portrayers left Midway due to royalty disputes. Ho Sung Pak (Liu Kang and MK1 Shang Tsung), Phillip Ahn (MKII Shang Tsung), Elizabeth Malecki (Sonya Blade), Katalin Zamiar (Kitana/Mileena/Jade) and Dan Pesina (Johnny Cage and Scorpion/Sub-Zero/Reptile/Smoke/Noob Saibot) were not involved in the production of Mortal Kombat 3, resulting the use of new actors for Liu Kang (Eddie Wong), Sonya Blade (Kerri Hoskins), Shang Tsung and Sub-Zero (both played by John Turk) in Mortal Kombat 3. In Ultimate Mortal Kombat 3, all of the male ninjas would also be played by John Turk, while the female ninjas (Kitana, Mileena and Jade) were played by Becky Gable. Johnny Cage would be played by Chris Alexander in Mortal Kombat Trilogy.
Carlos Pesina, who played Raiden in the first two games, did not appear in Mortal Kombat 3 as a penalty for his involvement in the rival game Tattoo Assassins, but was still employed by Midway. His character returned in Mortal Kombat Trilogy, but using new sprites.
To fit on the Game Boy major sacrifices had to be made. Only nine of the original fifteen fighters (Kano, Sonya, Sub-Zero, Cyrax, Sektor, Sheeva, Sindel, Kabal, and Smoke) were available, only five stages existed, there were no button-link combos, no Motaro sub-boss, and no finishers outside of fatalities and babalities. Shao Kahn used his moves from Mortal Kombat II. Although rated M for mature, this version did not include much of the overt gore and violence seen in its parent systems but kept some of the "burning" fatalities (immolating a defeated opponent down to just a burnt skeleton). However, the graphics are superb for a Game Boy title, with smoother animation and greater attention to detail on the fighters than the older MK titles for Game Boy.
There was also a scaled down Game Gear version of MK3 which was never released in the US. Only Europe and Japan saw a release, and it is rare to find; a complete packaged version can be seen on Internet auctions for as much as $90. It is almost the same as the Game Boy version, although it includes blood and gore, is in color, and features Noob Saibot as a hidden character. There was also a port for the Master System, which is nearly identical to the Game Gear version, although it was only released in Brazil by Tec Toy, distributor of Sega's products in that country.
There were 2 different versions of MK3 for the PC. The first was a DOS version, which is unique as it does not closely resemble any of the other ports. It features good animation, sound, graphics, and it implements the gameplay of the arcade with a high level of precision. This version contains a hidden redbook audio track with a narration of a story in reverse. The second version was a Windows version. It is a direct port of the PlayStation version of the game, featuring the same menus, identical sprite sizes and qualities and the same gameplay as the PlayStation version.
MK3 for Windows and for PlayStation is also the base for Ultimate Mortal Kombat 3 for the Sega Saturn. These games feature the same sprite sizes and qualities and almost identical menu systems but the Sega Saturn version has the additional content from UMK3 roughly added in as well.
Mortal Kombat 3 is also available as part of Midway Arcade Treasures 2 for the GameCube, PlayStation 2, and Xbox. It is also available as a part of Midway Arcade Treasures Deluxe Edition for the PC (this title included a 'making of' documentary about the game), and in Midway Arcade Treasures: Extended Play for the PSP.