
Originally Posted by
whoopeeragon
Everyone seems to enjoy arguing what makes a Final Fantasy game, so here's my share of the pie...
From my research and playing, there is only one major theme which is shared by ALL main-stream Final Fantasy titles, and that's crystals, and they generally play a major part in the plots as well. Not even chocobos or tonberries or airships come as close.
SPOILERS FOR PEOPLE WHO HAVEN'T PLAYED THE GAMES/RESEARCHED
FFI - All four of the main characters have a Crystal, and Garland has one as well. The main characters channel power through their four crystals into Garland's to get the world out of a time loop.
FFII - You get Ultima from them, and stat-boosts. Crystal Rod is essential to the obtaining of those.
FFIII - Eight Crystals in total, 4 Light, 4 Dark. A crystal choose the main cast to restore power to the Crystals, and the Dark Crystals aid in making the final boss kill-able.
FFIV - Same as FF3, eight Crystals. Well, 18 in total, counting the one which teleports you to the Moon and the 9 which are able to restrain Zeromus' power. Last one enables you to kill Zeromus.
FFV - Four Crystals, each controlling one of the world's elements. Was responsible in aiding to seal Exdeath, and later restoring the world.
FFVI - Exists as Magicite, the crystals used for summoning Espers after their flesh has deteriorated into the crystal. Used by the main cast and sought out by the villains throughout the game.
FFVII - Materia, life energy of the Planet crystallised into a solid form. Can cast spells with them, summon etc. Also a major plot device with the Holy and Meteor materia.
FFVIII - The huge-ass Crystal held inside the Lunatic Pandora; spawns the periodic Lunar Cry which brings monsters down onto the world's surface. Seen as an evil force in this game.
FFIX - The source of all life, and allows the few summoners to do their job. Also a plot device with the Terrans sealing themselves within Crystals to await reincarnation.
FFX - Not so much a plot device, but a tool. Crystal spheres are used as save points, save memories and events and even as keys.
FFXI - Used for synthesis when seen as a tool, and present as the Mothercrystals when seen as a plot device. In fact, too many types of Crystals to go into detail, but there are also Protocrystals, Gatecrystals, orbs and magicite.
FFXII - Crystals known as magicite, storing the magic energy known as Mist. Responsible for the running of machines and city-life, and also how the the Ivalice gods, the Occurian, gazed onto the world. A major plot device.
FFXIII - Seen as a plot device at it's core; the fal'Cie are run on crystals, and the main cast gain the power of summoning their Eidolons from their crystals.
FFXIV - Currently seen in synths and aetherytes. Also seen in a couple of storyline quests.
SPOILER END
Debate it however you want, but that's my interpretation of what lies at the core of every FF game.
Every game is different, so different people will like it. I liked FFXII, XIII, X and VIII, but I disliked VI and VII. Again, these are all open to your differing likes and dislikes, and the media cannot control that, no matter how hard it tries.