It's difficult to place the game that started it all low on this list. There's quite a bit that Final Fantasy does right, make no mistake. The setting is pure high fantasy, and the story is too -- at least, what exists of it. Along with Dragon Quest, the original FF pretty much ensured RPGs would go hand in hand with medieval, European-type settings for years to come. The battle and job systems set the tone for countless RPGs to follow as well, and despite being linear in nature, the game still provides players with a good deal of freedom to explore its world, unlike the much maligned Final Fantasy XIII.
Apart from being the first in so many ways, these systems still hold up and make for a good game today, -- particularly if you happen to be playing the GBA version of FF, with its more streamlined magic system. It's only natural, though, that later games in the series would improve on what this one started, including the themes of justice and lust for power, the crystal motifs, and job classes. Still, the original Final Fantasy provides an enjoyable experience, even if it is bare bones.
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