Joel is tasked with leading Ellie across wastelands and damaged buildings, fending off attacks from human bandits and zombie-type creatures known as Clickers and Bloaters along the way, to deliver her to a group of freedom fighters called the Fireflies.
The pair grow close over the course of the game, and after 18 hours of gameplay, The Last of Us seems set for a traditional ending in which a cure is developed for the zombie virus using Ellie's immunity and everyone lives happily ever after.
But, in a twist that developers Naughty Dog admit didn't test well and wasn't their original plan, Joel pulls Ellie out of surgery after learning that she would have to die to create the vaccine, shooting the surgeons and anyone else who comes in his path.
The last scene ends ambiguously, with Joel lying to Ellie about what happened. Unlike other games, there are no alternate endings and gamers are forced to follow one path.
Gamers took to Twitter to question and praise its final moments.
Everyone who likes the ending of The Last of Us loses all credibility to have any good opinion.
The Last of Us' ending had me almost ripping my hair out omfg
That was the ending of The Last Of Us??? AFTER ALL I WENT THROUGH??? I HAD TO FIGHT 2 BLOATERS FOR GODS SAKE AND THERE'S STILL NO CURE
Just completed The Last Of Us and that ending is mindblowing, best game ever made easily
Crikey. Finally finished The Last of Us. That's quite an ending. And not what I expected at all.
Reviewers also headed online to discuss what the ending meant.
"Joel lies because, if he didn't, Ellie would try to find a way to sacrifice herself and make the cure, thus Joel would lose her," wrote IGN blogger Ezio513.
"The ending isn't simple, you have to look at the overall picture, and kinda dig to understand what it all means and what it means to you and what you take from it."
In a discussion on Polygon.com, Chris Plante wrote: "It's a horror story, right? In the end, Joel's taken this young girl hostage and turned her into his dead child."
Forbes writer Paul Tassi said he struggled with the "difficult" ending that was morally ambiguous - but admitted it was the right way to end the game.
"I view Joel's actions as more selfish than anything else. He's doing it for her, to some extent, but mostly he's doing it for him. He couldn't stand to lose a daughter twice, and even if he has to murder dozens of innocent, well-meaning people, kill untold millions by proxy from a lack of a cure, and tell Ellie a lie that if she ever discovered was untrue, would ruin her, he's going to do it.
"This is not heroic, however it may look," he wrote.
Naughty Dog's developers have hinted that a sequel is in development, but said it is unlikely to feature Joel or Ellie.
* What do you think of The Last of Us? Post your comments below.