During the game's early development, there were plans to include a "Samurai Shodown Team" made up of Haohmaru, Nakoruru, and Galford. The idea for the team was dropped due to concerns about the first Samurai Shodown's popularity:

"Samurai Shodown was just coming out. So, it was kind of like, are these characters going to be super popular or not? And when it comes to the King of Fighters series, really it’s about who are the all-stars of SNK, right? What popular characters are we going to put in there above everything else? What’s going to sell?

So at that time, we didn’t really know if these characters were going to help increase sales, because you had to wait an entire year or so to see what characters were popping up as everyone’s favorites."
Contributed by DrakeVagabond
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Ryuhaku Todoh from Art of Fighting, Duck King and from Fatal Fury, and Heavy D! from the previous game, appear in the background of the England stage.
Contributed by DrakeVagabond
The PlayStation port of the game has extra features that were not in the original Japanese version, such a level select and an improved English translation, which was one of the biggest issues from the Neo Geo version. The port also fixed areas of slowdown, the lower-quality graphics from previous versions, and missing frames of animation.
Contributed by DrakeVagabond
Geese Howard from Fatal Fury was originally meant to appear as a playable character, but the developers abandoned this plan, citing "various considerations at the time" in retrospect as the reason for his exclusion. Geese would eventually appear as a playable character in The King of Fighters '96.
Contributed by DrakeVagabond
While most Fatal Fury characters use different vocals (primarily taken from Fatal Fury 3 which was the newest game out at the time), Kim Kaphwan still uses his old Fatal Fury 2 vocals, as he was not present in Fatal Fury 3.
Contributed by MightyKombat