It is basically Doom 3 with a silly story and a douche bag of a protagonist.
Prey is not, and doesn't try to, be an ambitious game. It is safe to assert that it is a silly spin off of Doom 3. Nonetheless if you are a Doom 3 and Quake fan but don't quite want to replay those games, Prey will do a pretty good job at encapsulating those game experiences.
Graphics/audio:
The developing team of Prey made it very clear that Prey runs on Doom 3 engine, this is definitely true when you just look at the graphics. Everything you see, all the details in the texture, can be expected in Doom 3. This doesn't mean it is beautiful or anything, it just means that the metal objects tend to be shinier. Gore is present in the game, but then again, it is pretty much just like Doom 3. No more, no less.
The audio is once again just like that of Doom 3's (you can start to see how little this game tries to be outstanding.) The way things echo, the spooky distant roars you can occasionally hear, all copied from Doom 3 wholesale. Presentations wise, this game is pretty much Doom 3.
Gameplay/ story
Although it is very apparent that the developers put more attention into making the Gameplay more unique, it still doesn't stray too much away from Doom 3, although some of these new features can be quite interesting.
The game is a first person shooter that runs on the Doom 3 engine, so combat is incredibly similar to that in Doom 3. Since there is no real human weapon in the game to use, the alien weapons will constitute your whole arsenal. Many of them are fun to use, like the tiny bug-like aliens that can be used as grenades (and they still move when you are holding them), or a sniper rifle that looks like it is alive. The guns are creative and fun to look at, and they enlarge the range of tactics you can employ in battle. The game makers did a good job on this aspect of the game.
Another unique feature in the single player campaign is the liberal use of gravity. You will frequently encounter shiny ladders on walls that you can walk on and the camera angle will flip with you as your perspective of the room changes. In other words, you will never feel like you are upside down from your point of view. A varied version of the ladder is the gravity nodes that you have to shoot to change the gravity in the room. Gravity changes can lead to some intriguing puzzles, but also confusion. You will have to give some thoughts into how you want to reach a place and execute them step by step. You have to make sure that you remember all your plans because if you forget them you will be instantly lost. For me, at first this feature looked promising, but then gradually started to piss me off. It is even more infuriating when you are walking on the gravity ladder and thinking about what step to take next, only to forget about what you were going to do because some enemy spawned behind you.
In Prey, you don't ever really die. When you run out of health points, you will be teleported to a dimension where you can use your spirit bow to shoot some flying monsters to get more health. After a certain amount of time you will be transported right where you perished and fight the same enemy again. You can choose to not shoot the flying monsters when you are dead and still revive with some health given. This feature is rooted in the silly story of Prey, which I will address later. The fact that you can never really die makes victories much less gratifying. Many might find themselves asking, "what is the point?"
The plot is silly yet somewhat deep. The whole game is weaved by two themes: identity crisis, and hero's journey. You play as Tommy, an unlikable douche bag who doesn't like to be a Native American. An alien spaceship called the Sphere abducted Tommy, his girlfriend, and his grand father or something. Obviously, Tommy somehow escapes the grasp of the aliens and tries to save his girl friend. As the game progresses Tommy gain more Native American spirit powers to do different kind of things, even though hates being a native American. In the end he uses that power to save the world. Surprising, eh?
Multiplayer:
I was not inclined to play the multiplayer after finishing the single player part of the game.
Fun ways to play this game:
It is evident that Human Head studio focuses mostly on developing the single player portion of the game, so I suppose that is the most fun portion of it.
Conclusion:
The fact that this game is so close to a recycled version of Doom 3 makes it hard to recommend. I would vehemently advice against anyone who wants to buy this game because it really isn't worth the money. If you really want to try it out, rent it.
Oh, one last thing, the spirit walk ability in the game is pretty stupid.