Naughty Dog's new game will have a 12-16 hours long campaign with even more play time depending on your play style.
Arne Meyer from Naughty Dog discussed the campaign: “We’re definitely looking at more than 12 hours, maybe 12 to 16 right now is what we’re looking at. It really depends on how you play. You can play a little bit slower if you try to approach situations stealthy, if you really wanna explore the environment and scavenge, that’s going to add more time too.”
Here's an interview with Naughty Dog Community Strategist Arne Meyer.
