The gameboy version adds Nakoruru from the Samurai Shodown series as an unlock-able character.
A small continuity mistake in the game: After three fights, you are treated to a small story sequence where Vice informs your progress to Rugal. However, she claims that your team has won four fights!
This was the last King of Fighters that, following Art of Fighting's tradition, allowed you to tear the clothes of said game's female characters whenever you finished them off with a special move. Ah...the things they could get away with in the good ol' days! ;)