The only game in the series thus far to use a "Key Word" system, in which words learned during certain conversations trigger events when mentioned to someone else.
The game that was released in America for the Super Nintendo called Final Fantasy II was actually the original Japanese Final Fantasy IV. This, the ACTUAL Final Fantasy II, was an NES/Famicom title not initially released in the states.
A rare example of a Final Fantasy game that doesn't have an experience points system, instead featuring the ability to level up different attributes of characters through their usage. For example, using the "attack" command frequently in battle will give your character a better attack rating, while using a magic spell plenty of times will allow that spell to become more powerful.
This was the first game of the Final Fantasy series to feature the recurring elements of a character named Cid, as well as the first appearance of chocobos.
This game was not released in America until 2003, as a part of the Final Fantasy Origins Playstation One package.