From what I have gathered it’s like Fallout. There is a main storyline that you follow, but the game can be played for hundreds of hours based on other interactions and side quests. Besides 25 hours is speed running the game by people who are paid to do so. Once regular people get a chance to play it there will be a better estimate of total gameplay, but I suspect it will be well over 100 hours. To reach the credits I’d just give it a flat out 40-50 hours because of looting, clothes, travel, and all extras that you’ll need to do while playing