Fantastic game. Wonderful setting, tense atmosphere that really keep you on your toes, and an open (enough) map that rewards exploration and discovery. From floating around in micro-gravity, to crawling around rafters, to stealthing your way through enemies or blasting them to bits using a wide variety of weapons and tactics, Prey offers a great amount of diversity in the way to solve any situation. Upgrading your character can be done in a wide variety of ways, enabling a good amount of replayability. The story is a bit cliche, but is interesting enough to search out the bits of lore spread throughout the levels, usually in the form of emails and notes.
All in all, highly recommended.