Given the nature of exploration aboard the Talos 1 in Prey, your mileage will vary in terms of playing time.
Ricardo Bare of Arkane Studios confirmed via Reddit that the play-testers were able to finish Prey in 16-24 hours, with some members of the team taking as long as 34 hours.
Looks like there will be no shortage of time surround by creepy aliens.
Prey (2017) How Long Is The Game? - GameRevolutionWATCH GALLERY