These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Mortal Kombat 4
Anticlimax Boss: Shinnok. He just didn't have the fear factor of guys like Shao Kahn or Shang Tsung, and on lower difficulty levels, he doesn't even use his special moveset changes. Especially jarring since he, as a fallen Elder God, he is supposed to be leagues above them both yet comes across as a 2nd-rate Shang Tsung. Even Ed Boon admits that Shinnok probably shouldn't have been the Final Boss of 4.
The Game Boy Color version was a cheap and unplayable bastardization because of technical and graphical limitations. With "music" that's complete ear rape and makes music in pirated bootlegs look good by comparison. Prepare yourself.
Replacement Scrappy: Jarek was hated by fans who felt that he was nothing but a re-hash of Kano's moves. This is because he was originally supposed to be Kano, but the developers wanted more "new" characters, so they reskinned him.
Tanya and Reiko were this, mainly in the eyes of the fans of Kitana and Noob Saibot respectively, because they wanted the latter to appear instead of the former. Surprisingly enough, it didn't last long and got Rescued from the Scrappy Heap, becoming fan favorites because of their distinct personalities (Tanya being a traitor to her own realm and Reiko of an enigmatic enforcer who puts suddenly Shao Kahn's helmet in his ending).
Tough Act to Follow: Coming up after Ultimate Mortal Kombat 3. This game is supposed to return to its' dark atmosphere and having exclusively two fatalities per character, as well as two stage fatalities. Sadly, this game lacked the charm of the first three games.