Warning! Spoilers for Mortal Kombat below.
Mortal Kombat brutally killed off a large number of characters in order to live up to its R rating, causing a sequel problem for the franchise's future. The movie brought classic video game characters to life, but as many were swiftly killed off during Mortal Kombat's ending, fans may have less of an incentive to come back for a potential sequel.
The movie expands upon the world created in the arcade games. MMA fighter Cole learns he is hunted by ancient warrior Sub-Zero because of the dragon marking he was born with. Cole realizes that a handful of people all over the world carry the same marking, which signifies they are chosen as Earth's greatest champions to take on the warriors from the Outworld. Whichever world wins the ultimate battle, known as Mortal Kombat, gains complete control over the universe.
By Mortal Kombat's ending, nearly every champion from the Outworld is defeated in battle — even iconic villain Sub-Zero. Earthrealm even lost one of its own champions. The final scenes of Mortal Kombat show the movie is banking on a sequel to continue the story, but by killing off so many characters for the shock factor, Mortal Kombat sacrificed many of the key figures who would've drawn audiences back to a sequel.
The whole appeal of Mortal Kombat was to see these characters fight one another. In fact, Mortal Kombat's marketing campaign heavily revolved around the appearance of Sub-Zero, heavily implying viewers would see protagonist Cole take on the warrior. In a way, Cole acted as an avatar for video game fans, as he allowed them to relive fighting Sub-Zero in the game. But that idea was short-lived as Cole and his ancestor Hanzo teamed up to take down the warrior in the movie's brutal finale. Prior to that, game characters like Kano, Kung Lao, Goro, Mileena, and Nitara were killed in a marathon of fight scenes that took place within a matter of minutes.
Those deaths were overly gory as is the Mortal Kombat formula, which created for fleeting entertainment. But in the long run, those deaths meant beloved game characters were gone for good. In the movie's final moments, Lord Raiden tasked Earth's surviving characters with finding new champions for the planet, in a moment that teased the introduction of fan-favorite Johnny Cage. Beyond that, the movie already used up a good portion of its most popular video game characters. That means that a potential Mortal Kombat 2 may have to utilize lesser characters, which is less of an incentive for viewers to return. That creates a real problem because, without that pressing reason to return, a potential Mortal Kombat sequel may not be as anticipated as the reboot itself was.