Not sure why people are still talking about the violence being the only redeeming feature of mk games. MK1 was rather simple, but still fun to play. but mk2 and mk3 were greatness. Every single attempt at copying them failed. Time Killers, Time Slaughter on PC, Blood Storm, Eternal Champion, etc. They all failed HORRIBLY and barely anyone remembers them. They all felt super weird and felt choppy as fuck compared to how smooth MK's digitalized graphics were at the time. Of course it wasnt as smooth as the sf2 engine, but it was quite something, considering MK1 was made by like 5 dudes with their friends, halloween costumes and no actual support from Midway. They worked on the game on their own after their regular work day until some exec saw the game running on a dev board and decided to send it out for testing.
MK's sudden arcade release was epic. It just appeared in arcades out of nowhere. Incredible graphics, super fast gameplay (compared to how slow SF2 World Tour felt back then, super easy to pick up and play (regular joes could easily pull mk's moves instead of rolling joystick motions used in sf2). It was a blast to play with friends. The whole mystique and super iconic characters were cool, for the time.
MK2 took things to the next level. MK3 kinda soured a lot of people, but it was a victim of midway execs pushing the team hard for another sequel before the release of the movie, midway cutting corners on the arcade board (the team wanted more memory, but midway was like "lol no, we want more profit on each board") and franchise fatigue. 2 sequels in 2 years is a lot, and the mk team was super small back then.
Mk4 was even more rushed to the market, 3d stuff was new at the time and it felt very primitive compared what was out at the time. MK4 was so rushed that they shipped the finished arcade cabinets without the actual game boards inside, they shipped the boards after a few weeks to be installed manually by the arcade ops. The first version of the games were unfinished. They lacked endings, had no real final boss, some characters had no special moves, and some moves would randomly crash the game. It was madness
I can't blame the dudes for running out of ideas. The 3d fighting games market was flooded to death by wannabes and fighting games were starting to fade out in mainstream popularity compared to the rise of 3d fps games, jrpgs and survival horrors. Also, arcades were starting to die when MK4 came out
It's very basic now, but at the time, it felt like the fastest, craziest, best looking game ever. The gore was just the icing on the cake.