One of the keys to its success was the soundtrack. Music hadn’t been an important part of fight films up to then. The focus was on the action and during the actual fighting, there was little if no music. You were supposed to get into the fight because you enjoyed the moves and choreography.
Mortal Kombat was such a franchise by then that it needed a little something extra to get the adrenaline flowing. Most of the people who watched it were familiar with the moves and actions, so it made it more difficult to become emotionally invested.
They made up for this by introducing a fast passed techno soundtrack that complemented the action. Oftentimes, the music was actually created for that specific scene. The pinnacle of this in my opinion was the fight between Johnny Cage and Scorpion. The music used the original Scorpion catch phrase and then let loose with the techno.
Mortal Kombat was one of the first film to do this and it changed the fight movie industry because of it. You can’t watch a fight movie anymore without having techno music blaring with every scene. The fights are even choreographed to the music, so that moves happen at certain beat points. Mortal Kombat used their soundtrack to bring audiences closer to the action.