It's pretty difficult to begin with a game like Ocarina of Time, if only because so much has been written about it. Upon its release in 1998, it was heralded as the best game ever made, and in my opinion it's still in the top five at least. There are so many things going on in this game from a technical and artistic perspective that even though it's been a solid thirteen years since the game came out, so many things in it were done better then than almost anything now. That's not nostalgia talking, either – I had never played Ocarina of Time until 2005.
What makes Ocarina of Time more than simply a great exercise in digital play and exploration is the way that its central gameplay is fused to such an ingenious narrative structure that, I'd contend, stretches over the entire Zelda series. Thinking of Zelda games as a standard "first game-second game-spinoff-sequel"-type structure is probably incorrect. What I'd like to propose is that that "Legend" signifier right there in the title has considerably more meaning than that.
Consider: The Legend of Zelda has always been imbued with a hefty amount of religious imagery. The first game saw Link cast as a digital crusader, shield emblazoned with a cross and everything. The very structure of each game is appropriately mythic, and not in an overt or self-conscious way like, say, God of War (and unlike God of War, Zelda isn't exploiting its mythic conceit for the sole reason of making cool fights and gore fly everywhere). Indeed, the very world of Zelda seems to have many similar qualities to, say, a Greek or Roman legend, filled as it is with Gods, religious symbolism, and swords that repel evil. The Legend of Zelda isn't the first piece of media to rip on the Hero with a Thousand Faces, but it's certainly the first (and continues to be the best) at integrating the core conceits of the mythic quest into digital form.
It can perhaps be taken for granted, since Zelda essentially laid down the framework for every fantastical adventure game that has come after it, but there is still so much going on in the series that makes it vital. Let's examine Ocarina of Time first, as this is the game that I feel has perfectly cemented that mythic structure, so much so that every game that has come after it in the series has to owe some debt to it, and because Ocarina's structure is integral to the understanding of what, exactly, Miyamoto and Company are trying to do with the series.
Ocarina of Time is the quintessential Zelda storyline: starting off in the forest town of Kokiri Village, Link has always known he was different from the fairy folk who lived there. When he is called upon to heal the Great Deku Tree, the guardian spirit of the forest, he awakens as the story's mythic hero, who has to travel the lands cleansing it of evil and restoring peace and order to the land. This results in what has often been referred to as (derisively in other media) "video game narrative," as Link has to travel the countryside, conquer dungeons, collect medallions, and eventually overcome the evil embodied by Ganondorf.
It's a setup that borders on cliche, but it's not cliched (or if it is, it's intentional), as Ocarina of Time is consciously calling to mind the structure of the Hero's Journey. This alone isn't reason enough for Ocarina of Time to be considered great (I actually have quite a few reservations about the Hero's Journey structure), but for the way in which OoT engenders such a deep, personal connection to the player without resorting to overtly RPG-like game structures. Link is the perfect synthesis of an external avatar, unconnected to the player (the game never lets you be "evil" or to do anything outside the moral bounds already set in place), while simultaneously standing in for whoever is playing the game by offering up the illusion of freedom and exploration. It is an illusion of course – as it is in all videogames – but Ocarina of Time and the Zelda series in general have always succeeded at allowing the player to feel in total control of their own destiny.
That's not to say that the journey is easy. Zelda games have always been as much (or moreso) about using cerebral ability to get by as much as it has been about pure action. Each dungeon is set up as a kind of "test" of the player's will, and even though the dungeons perhaps don't make too much sense in a literal kind of way (why would anyone design these things this way – so complicated and yet still penetrable?), but in a mythic sense, Miyamoto has pulled off a genius trick: the game ultimately is about the player's journey through the myth, and Ocarina of Time invites participation from the player rather than having any external force that controls progression.
What's most impressive about this is just how linear Ocarina of Time really is – you're always moving forward, progressing, and the game doesn't really allow you to tackle things in any order. There's the sense, reinforced especially by comments from townsfolk and other passersby, that the "Hero of Time" is a cyclical concept, and that in a way, whatever you do in the game has already been done before by someone else. This makes the necessity to, say, find the hookshot before going to the Water Temple, feel organic and actually quite revelatory, as Nintendo has pulled off the impossible – making a linear adventure with little or no choice involved feel involving, natural and player centric.
My thoughts after having played a few Zelda games is that the idea that there's an actual timeline to the Zelda franchise is misguided at best. Indeed, I think that because of those aforementioned Hero of Time comments, and the games that have come before and after Ocarina of Time, that The Legend of Zelda is an experiment in narrative perspective while never being overtly explained as such. Consider this: so many elements recur throughout the Zelda series. So many of the narratives are similar while being just a tiny bit different (or in the case of say, Majora's Mask, hugely different). So many of the story "beats" are set up in similar ways while changing it up just a little bit. This is the primary criticism against the series, that it never changes.
But what if what we're getting is the same legend, told over and over again, with a different implied narrator or audience for that legend? That is, what if Ocarina of Time is the austere, "biblical" version of the Legend? What if The Wind Waker is designed with a child audience in mind, or told by a child? What if Twilight Princess is a version of the story of Ocarina of Time, twisted and warped by the flow of time as in a cosmic game of Telephone? The cynical might say that this is a conceit that allows Nintendo to avoid truly innovating with the series, but a) that's bullshit, and b) I would say that an exercise like this automatically makes the series innovative, if not one of the most important pieces of fiction in any medium.
The reason why Zelda, then, is ultimately so integral to any discussion of video games, is the way in which it has and continues to pull off a daring narrative conceit while tying that narrative specifically to a type of storytelling that can only be done through video games. Everything here is about fluidly changing a narrative based on player interaction, something that can't be done in any other medium. The fact that the games in the series are also generous enough to do this with gorgeous aesthetics (seriously, despite some blurriness, Ocarina of Time holds up better than almost any other 3D game from the era) and some of the most amazing music ever composed is simply icing on the cake.
The interplay of music making and progression, the fact that swordplay is tied not to killing arbitrarily but simply surviving, the fact that you get to ride a horse across a grand landscape while the sun sets and everything turns a hue of orange, the way in which the ominous music of the final castle grows louder and louder as you progress up its stairs, only to find Ganondorf sitting, playing the organ, the way that the game manages to also have a perfectly executed time travel narrative, making Ocarina of Time one of the most successful interactive bildungsromans of all time (and I'm certain that more than a few kids of the 90s came of age with Ocarina of Time right alongside Link), the wistfulness of returning to your childhood home as an adult, the way in which former acquaintances join you in battle as sages later on, the sheer beauty of the game and making your way through its epic storyline and coming to its poignant conclusion, the way that Zelda herself seems to play a huge, behind the scenes role, perhaps even doing more than Link himself throughout the storyline, or how the game still is generous enough for witty humour, for dark, foreboding caverns, for Hover Boots and magic, for fairy bows and hookshots, the way that the game lasts for well over twenty hours but feels like it goes by in less than half that, the sheer, unbridled joy of navigating a 3D space with Link for the first time or the fifteenth, did I mention the music, MY GOD THE MUSIC IN THIS GAME, and finally, and ultimately, how goddamned fun and wondrous the game is. These are the elements that make Ocarina of Time great – it's a perfect synthesis of everything that games should be doing in one package. The fact that it's also hugely important and innovative is what puts it into that upper echelon.