Assassin's Creed Odyssey will be even longer than Origins, according to game director Scott Phillips. Speaking in the video above to Game Informer, Phillips is asked if the game is about the same length as Origins, and answers "No, much longer."
You can find this at 3:06. Phillips doesn't elaborate on that, but he does explain that the map is bigger and more packed with things to do. "There's a ton of stuff to explore and find and discover." We pretty much knew this bit already. Odyssey's map of Greece will of course feature numerous islands, and the return of naval combat. Check out the full map in the video below from my hands-on earlier this year:
The definition of an odyssey is "a long and eventful or adventurous journey or experience", so I guess they're fulfilling that by making the game longer than Origins' 27-30 hour standard playthrough (it took me more like 38, doing some side content along the way, like the pyramids).
I'm not sure about you, but I found that to be long enough. I feel like Odyssey is now going to eat at least a month of my game-playing time—which is good value if you only play three or four games a year, but kind of a challenge if you keep a list of games you plan to beat before you die (hello).