I've been following this game for the entire year and I was so excited about it when I got it for my birthday. I started playing it just a few days later.
What intrigued me to begin with were all the parallells to Bioshock. Scary things happening in a confined space, experimental drugs that enhance people, and a mysterious threat. But as soon as I started playing, Prey came into its own and completely separated itself from Bioshock. They are both FPS with RPG elements. They are both dipping into the horror genre, Prey even more so going into survival horror as it is. Prey is scarier than Bioshock. While Bioshock created tension it relied more on jumpscares with the Spider splicers than anything else. Prey has the affinity of creating the psychological horror of never knowing what to expect around the next corner.
Being a little bit of a survival horror game, Prey had an ammo problem. Several times I ran out of ammo because there just wasn't enough crap to scavenge and recycle into clumps to make ammo from. That's until I read up about other people having ammo problems and learned to abuse the Recycler charges and turn doors and cargo and furniture into clumps to make ammo from. The space station was pretty darn empty when I was done with it, but afterwards I had no problems with ammo anymore xD
Storywise Prey is really, really good. Without spoiling anything, you play as Morgan Yu (doesn't matter if you're male or female - you're Morgan Yu) and you work at a space station. Yay, you! When you wake up things are weird and you start trying to figure out what has happened. This is hard because you're suffering from memory loss and it's up to you who to trust (even which version of yourself to trust), and the choice who to trust will change several times over as you learn what happened on the space station while you were out.
The game has multiple endings. One of them can come about waaaaaay ahead of the others and even without solving anything. You can just leave. There's one more ending where you can leave without actually solving anything, but that's the asshole ending. The other two versions completely depend on who you choose to trust in the end. I did both of them and in total three endings. I liked one of the true endings better than the other.
The final parts of the game where you choose which person to go along with had me going WHAT THE SHIIIIIIIIT!!!! several times. Because holy shit. Wow. I have no other words. Just wow.
No matter which true ending you choose you'll end up with exactly the same little cutscene after the end credits. The fact that it was the same no matter what you did at the end cheapened it a little bit. But if you only do one ending this cutscene definitely adds to the whole "what the frick. what is real" vibe of the game.
Prey is excellent. I loved it. I even missed it in the days that followed after I had finished it. Go play it.