The Last of Us getting a PlayStation 4 version didn't come as much of a surprise, even without the deluge of leaks and rumors. But just because the idea seems obvious doesn't mean the road was easy. Creative director Neil Druckmann recently described just how hard the task was, in some unexpected ways.

“I wish we had a button that was like ‘Turn On PS4 Mode’, but no,” Druckmann told Edge. “We expected it to be Hell, and it was Hell. Just getting an image onscreen, even an inferior one with the shadows broken, lighting broken and with it crashing every 30 seconds… that took a long time. These engineers are some of the best in the industry and they optimized the game so much for the PS3’s SPUs specifically. It was optimized on a binary level, but after shifting those things over [to PS4] you have to go back to the high level, make sure the [game] systems are intact, and optimize it again."

He said that even after optimizing, the two versions had to be run to make sure nothing was broken in the process. The task ended up ballooning past its original size, from a few programmers tinkering with the idea to a "significant programming staff" to port everything over. Druckmann says the team was very careful to preserve everything just as it was, which means they haven't gone out of their way to tweak things that were knocked in the original.

“Star Wars comes to mind. I’m more of a fan of the original cut and Han Solo shooting first," he said. "I have so much attachment to that one that any shifts in the dialogue, or even in the moment-to-moment gameplay, [mean] something about it feels so different that it becomes inferior in my mind. It’s only subjective, but there’s something nice about saying, ‘We’ve finished it’. That’s what we put out there, that’s the final experience – now it’s just about a locked frame rate and all the hi-res textures and assets our amazing artists created. I would like to say the game is the game, so I’d like to just bring it over to the PS4 and get a more solid version of the same experience.”