The exact moment when Ocarina of Time is completed, according to timekeepers at the Speed Demos Archive, is when Link thrusts his Master Sword into Ganon's skull.
That's after climbing the castle as organ music echoes through its chambers, after the lightning-bolt tennis match in the uppermost room of the tower, after the death-defying dash down the escalade with Zelda in tow, after the entire gothic structure collapses under its own weight and after that unforgettable moment at ground zero.
In terms of boss battles, it's exhaustive; nearly a full hour demanding watchfulness, precision and the right amount of dare when it matters most. The violence and unremitting challenge is startlingly un-Nintendo, even for a boss fight, but this final bloody gauntlet is the only way to bring Ocarina of Time - perhaps the greatest work from the greatest mind in games - to its full conclusion.
On first play, it will take anything up to 80 hours to finally thrust that Master Sword into Ganon. When you know your way around Hyrule, completing Ocarina for a second time takes about 30 hours - not quite the same odyssey but still a major commitment by today's standards.
Cosmo Wright can complete it in less time than it will take to read through this article, with no cheat codes, no tool-assists and no hardware mods. And he and his peers are more than happy to explain how.
Now a pre-eminent speedrunner, Cosmo has dedicated much of his adult life trying to get to the end of games as quickly as possible. His unnatural ability to subvert the mechanics of these digital universes is both uncanny and awe-inspiring.
Games may seem all calm on the surface, but behind the fašade is a cotton ball of code that ties everything together. Cosmo finds the loose ends of those strings, follows them, and emerges out the other side in a different time and place.
"It takes 100 to 150 hours for me to truly understand a game on a speedrunning level. Then I can decide if I want to continue pushing it or if the game is not for me," he tells CVG.
Cosmo has an unusual ability to get a sense of how unfastened a game's code is. He painstakingly picks away at the scenery and interactive elements, and if he determines that a game is exploitable enough, he then pours in hours of work to find that loose end.
"Understanding a game is from a speedrunning perspective is not obvious, it takes a while. I actually put about 150 hours into Banjo-Kazooie and then I thought 'this game is really good, but I'm not sure it's my style of game'.
"I wish I could tell you how many hours I've spent playing Ocarina, I really have no idea. Any number I give would be a complete wild guess. It's a lot."
On Saturday, January 12, organisers of the charity event Awesome Games Done Quick (AGDQ) had summoned Cosmo to take a seat in front of an old CRT monitor displaying Ocarina of Time. His playthrough would take place in front of a live audience at the National 4-H Youth Conference Center in Chevy Chase, Maryland, and under the gaze of a webcam.
"It takes 100 to 150 hours for me to truly understand a game on a speedrunning level. Then I can decide if I want to continue pushing"
That week, AGDQ 2013 had achieved a record of its own: the seven-day event became the most successful gaming marathon ever, raising $448,000 for cancer research. The vast majority of that money was generated through donations by people watching via live Twitch streams, as speedrunners from around the US ploughed through a punishing schedule of 121 games.
The event programme initially predicted Cosmo's slot would last 35 minutes.
At about two in the morning on the Saturday, Cosmo sat among the gathered speedrunners, in front of a camera broadcasting to thousands watching from around the world, and picked up the N64 pad.