At Gamescom 2016 Nier: Automata's Producer Yosuke Saito revealed that the game will take longer than 25 hours to complete, also offering more information on the side quests that'll feature.
In previous interviews Saito had said that the game would last for around 25 hours, however, the staff in Japan have allegedly informed him that it takes a lot longer.
He said that it is not necessary to complete the game's side quests to reach the ending, although to see the true ending players will "probably have to do the side quests as well", especially since there are multiple endings.
Elaborating on the side quests a little, he said there are short ones with standalone objectives requiring you to find an item or something similar, but there are also longer ones that may even have several chapters telling a story.
Saito also hinted that the resistance camp that has been shown off is not the only settlement in the game.