Released in Japan in 1991, this was the first Final Fantasy game to be released on the SNES. An 8mb cartridge showed off the abilities of the new graphics and custom chips, and this resulted in one of the most complex and imaginative storylines ever to appear in a videogame.

Story:
Cecil, a Dark Knight and captain of the Red Barons, an elite force of military airships sets out to capture an elemental crystal for his king. In doing so, the mage defenders are completely slaughtered. Troubled by this, he begins to question the Kings ruthless desire to capture the crystals.
However, the King soon gets word of Cecils distrust, and immediately removes his rank and sends him out to deliver a package to a small village.
But as Cecil enters the village the package explodes, destroying all and plunging Cecil into a lone battle against an evil empire.

Game System:
It continues with the 'fixed' character concept first introduced in FF2. However, this time round, the party members often change, giving the oportunity to play different character classes.
This is probably the last 'traditional' Final Fantasy game, in the way that the characters strengths and weaknesses are balanced according to their class: Paladin, Monk, White Mage etc. In later games, this balance is less emphasised, especially in FFVII where characters can eqiup all abilities.

Easytype or Hardtype?
There were two versions released in Japan, the standard version and 'easytype', which was intended for younger players and RPG 'beginners'. Many items, spells and abilities were removed, and some of the dialogue removed/censored.
The U.S release was based on the Easytype version and was renamed FFII. This began a confusing numbering policy that only stopped when the English version of Final Fantasy VII was released... as Final Fantasy VII.

Guides:

FAQ and Walkthrough
FAQ
Monster Treasure Chart
Shadow Fighter's Help File: This has got just about everything
FF2 Handbook: Algorithms, classes, monsters, tips...
All 5 guides in a zip archive (101K)

Square Artwork:

CG of Cid, Cecil Kain and Rosa
CG of Kain
Airship CG
Cecil
Rosa
Edge

Can I play it?
Final Fantasy IV was converted to the Playstation two years ago in Japan, and then re-released as part of the Japanese Final Fantasy Collection. However, it was ommitted from the U.S Final Fantasy Anthology. To find out more about this, check out the Final Fantasy Collection/Anthology page.
Luckily, it's not all bad news: the original Hardtype ROM has been translated and is freely available, and also, a Wonderswan version of the game is currently under development, although I'm not sure as to which version of the game it will be based on.