The debut of the ever-popular Final Fantasy series on the Super Famicom (SNES in America) only increased Square's popularity. Availible with more capabilities to more people, Final Fantasy IV put on one hell of a show to get anyone who played it through just once to get hooked for life. Featuring a splendid storyline, an array of characters, and (gasp!) 16-bit graphics, Final Fantasy IV was at least a mega-hit.
Gameplay: 10/10
You cannot put this game down. Although the story decides who's in your party at certain times, you can still do so many cool things. There are 3 wholly different worlds for you to explore in this game, and FFIV has it's share of secrets. Not to mention a never-before seen 5-party system, which adds a whole new dimension to battle strategy and fighting.
Music: 9/10
True, it's the SNES, but FFIV was great for Uematsu, producing a fine, orchestral soundtrack. (Well, it would be orchestral, but it's the SNES, so bear with it here.) Of course, you won't like every song, but most of the songs are wonderful. Definitely check out the orchestral versions.
Storyline: 9/10
Storyline is an essential part of any RPG. It makes or breaks one. The storyline made FFIV. It is a splendidly spun tale of good and evil by Sakaguchi. Despite FFIV having a bunch of characters, the most central of them are quite well developed, main villain included. You'll play FFIV at least twice for it's amazing storyline.
Final Dungeon: 8/10
This is probably the worst part of the game, and the fact that it still has an 8 says something. Bunches of bosses and enemies (and EXP+GP) lie here, accompanied with kickass music. There are also quite a few secrets, some ingeniously hidden, to find here too. A nice piece of work.
Final Boss: 7/10
No, this is the worst. Why? Well, in the easy version, the final boss is pretty easy. But in FFIV hardtype (FFIVj) the last boss is god-awful hard, almost as hard as FF2j's final boss. So it balances out to a 7. It's an ok boss fight, kinda fun, and you get to unleash cool stuff here too.
Replayability: 9/10
The only reason I can think of not to play this game twice is if you lose your sight and hearing. True, the stapled storyline will probably get to you after a while, but then you can always get all the White, Black, Call spells, items, and weapons if you want. It's really a fun game, and the hardtype version is pretty funny too (the easy version was released by Nintendo in America, which has a policy of cutting any and all funnies).
Overall: 9/10
A classic? Definitely. And with it's release on PSX in Final Fantasy Chronicles, it probably would get a 10. I haven't played Chronicles, however, but I'm sure it would be worth it if you haven't played FFIV. This is one of the greatest. Simple as that.