Before the developers could come up with names for the new characters Cyrax and Sektor, they were called Mustard and Ketchup respectively.
It shared the Best Arcade-to-Home Translation Award with Tekken in Game Players 1995 Holiday Edition (Vol. 8, No. 13)
Instead of being a ninja like usual, Noob Saibot was actually a palette swap of Kano, Presumably because almost all the ninjas were removed (except the new robot ninjas and Sub-Zero, whose appearance was changed),
The Windows 95 PC version released in September, 1996 was different from the 1995 DOS version in that it had "eight all-new characters, two new boss monsters and exclusive new encryption 'kodes' which enable players to alter control settings and intensify game play". It was in fact a port of the Playstation version. A $10.00 rebate was offered inside the retail box for those who had previously purchased the DOS version.
This was the only game for original Game Boy or for Game Gear to receive an M rating from the ESRB.
On November 30, 1995, Mortal Kombat 3, with the exception of the Game Boy version, was put on the infamous German index by the BPjS. For more information about what this means and to see a list of games sharing the same fate, take a look here: BPjS/BPjM indexed games.
In addition to the indexing, on June 12, 1997, the Genesis and PlayStation versions were also confiscated for violating §131 of Germany's penal code (for showing gruel violence against humans etc.)
The differences between the PS and SNES versions of the game are the following. In the PS version, they had Friendships and the SNES didn't. In the SNES, you have Shao Kahn, Motaro, and Smoke as secret characters. In the PS version, you only get Smoke. In the SNES version, there was a cheat that would let you play a mini-game. The PS doesn't have that. In the SNES version, there was a code that could let you do one-button fatalities. In the PS, that code is missing.
There are references to the game's creators in the game. Boon and Tobias (MK creators) can be seen on signs in the backround of the subway stage and the creators' names are on tombstones in the graveyard stage.
This was the first MK game to feature Sub-Zero unmasked and have a red mark on his eye. This made many questions however, and it wasn't until 1997 the question was answered in Mortal Kombat: Annihilation. This Sub-Zero was the original's little brother.
Lia Montelongo, who plays the ancient Sindel, as only 18 at the time the game was made.
The "Graveyard" stage that was found in the arcade version was scrapped for the 16-Bit versions due to memory constraints of the cartridge space. The rest of the gameplay and features remained intact.
The story of Stryker:
Originally, the character Kurtis Stryker was supposed to appear on MK1, but he was scrapped early in the development process when beta tests revealed player's interests on a female character (Sonya replaced him). Later, on MK2 Kurtis Striker made it almost to the final game, but had his name changed at the last time to Jax. Finally, Stryker would make his debut in MK3.
The game's "animalities" were inspired when upon the release of Mortal Kombat 2, Liu Kang's dragon-morph fatality started a rumour that all the characters were able to morph into some sort of animal as a finishing move. The creators thought this was a fun idea and included it in the game.
Rumours like this have always chased the MK series since the game's have always been heavily charged with secret features, however Mortal Kombat 3 is the only one in the series (to my knowledge) where the developers actually stepped forward to dismiss a rumour: that you could perform a "nudality" with Sonya Blade's character. Really!