"One of the systems designers just did his full playthrough to get 100 percent. So that's literally doing every single thing in the entire game, and he played 43 hours. 43 hours and he knows what to do," Barlog said. "He [worked on] a lot of the exploration content and the engagement outside of the core story. So he had not seen a lot of the core story stuff, that part was new to him, so that took a little bit. But everything else, that's pretty impressive considering he knew what to do."

"It's definitely larger than I intimated in the beginning of the game. I was like, 'Oh, it's not that big, don't worry about it.' We spent that entire time at the beginning, 'Don't worry, don't worry, don't worry!' [...] I think I just deflected for several years and just pretended. And then I would deflect it in the way of saying, 'I'm so worried, I don't think the game's gonna be that long.' And then we did our first sort of full gameplay test and it took five days, and we were like, 'Oh, man. Alright, what have we done?'"