Illusion of Gaia was released in the prime year of the Super Nintendo, and would have made a fine contender to Final Fantasy VI had Enix done a better job of marketing it. It's a stellar improvement over Soul Blazer, an excellent game, an excellent story, and generally miles above most other things Enix has released.
A good deal of the game's appeal comes from the fact that it uses real-world locations as dungeons. There are seven major dungeons (and a few minor ones); six of those are based on places like the Incan Ruins in the Andes, the island of Mu, the Great Wall of China, and so on. The locales are also given a great deal of life by the graphics. They're certainly above average for the time, and most importantly help to give the place its own unique exotic feel. Same goes for the sound - each major dungeon has its own theme, smacking appropriately of that locale's ethnic music. Furthermore, even some of the generic, reusable tunes are Really Rather Good. One theme in particular stands out among them, and that is a little flute dirge that, despite its minimalism, is definitely up there in the Top Ten Best and Most Memorable Video Game Tunes of All Time.
Gameplay-wise, it's unremarkable but certainly highly enjoyable. It's just complicated enough to hold your interest, and just simple enough to, well, to hold your interest. You've got your one playable character (who has a couple special moves he learns later), but to add some variety the designers threw in a couple of alter egos for him to transform into (which only have one function, which they accomplish admirably: being cool). There is no experience system - you get stronger by clearing out screens of enemies, which sounds like it could be tedious but isn't. Generally, the game is actually very fast-paced, even with the puzzles - another welcome touch! The dungeons are certainly excellently designed - the Incan Ruins is definitely one of the best video game locations ever created. In short, the game always has a way to keep you interested.
The plot starts out cliched, but later becomes quite strong. An interesting touch is that, though there is a distinct cast - seven recurring characters that you'll see frequently throughout the entire game - there is only one playable character. He also often functions as the game's narrator, and the first-person perspective is another clever idea. Most of the cast is surprisingly realistic, something that could be due to the game's dialogue (which is quite well-written, despite some translation problems). And some of the plot elements presented in Illusion of Gaia are hands-down extraordinary as far as games go. Illusion of Gaia was the first (if not the only) RPG to present the topic of slavery in a mature light, without being too preachy or dumbing it down too much. (Well, Nintendo's censors changed "slave" to "laborer," but still it's rather remarkably mature.)
But Illusion of Gaia's greatest strength may be something that could be called "emotional resonance" (however idiotic that sounds). It's little details in the game that make the difference - for instance, Freejia appears to be a beautiful city (literally; the flying rose petals are a very nice use of graphic capabilities), but if you look in the back alleys you will see that there is the ugly side of the slave trade going on in the midst of it all. (And the fact that a character initially remarks "People living in such a beautiful town must have beautiful hearts" serves to elicit a sense of irony instead of a sense of being beaten over the head with a moralistic point.) Another example - in the Incan Ruins, you find a broken skeleton of an explorer with a letter from the explorer's family in its hand; then, later, you meet with his family in some town, and they tell you how they miss him and how they look forward to his return. (It's genuinely touching - imagine that!)
Little things like that are present EVERYWHERE in Illusion of Gaia - clever combinations of snippets of dialogue, graphics, sound, and insinuations (relying on the player's mind to fill in the details - imagine that!) to cause an actual emotional impact. Often, such little things as coloring, backgrounds, clouds and mental association to the real-life locations is what makes a certain scene memorable. There are plenty of loose ends in the plot, however, instead of having the infuriating effect that they usually do, they make you try to resolve them yourself in your head. It's amazing just how many things this game gets right. Unfortunately, the game's ending was not one of them - it's a trite piece of crap that causes bewilderment after all the goodness that preceded it - but nevertheless, it definitely ranks as one of the finest games, not only of 1994, but of the whole 16-bit-era, and reinforces the idea that video games may someday become a viable storytelling medium, not just entertainment.