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.
Ensemble Darkhorse: Tanya is the only MK4 character that appeared in a sequel that wasn't Armageddon and she is well liked and was requested many times for DLC for Mortal Kombat 9.
Reiko too. The speculation his ending caused may have had something to do with it.
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.
The 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.