As a huge fan of first person shooters (arguably my favourite genre), I've had my eye on this little beauty ever since I first saw screenshots for it last year. Being a shooter with several groundbreaking new game elements, crossed with a macabre sci-fi horror storyline, it couldn't be more up my street - I just hoped and Preyed (sorry) that it would be the classic I knew it had the potential to be… and thankfully, it is - and then some!

Tommy is a Cherokee Indian living on a quiet reservation, but he yearns to be a part of the modern world, wanting something more, something exciting. Rejecting his Indian heritage, the only thing that keeps him anchored to his childhood home is Jen, his rather beautiful girlfriend. The story, and the game, begins, of all places, in a fairly grotty toilet out the back of the bar that Jen owns, and it's one of the few times you'll see Tommy's face, as he takes a good look in the mirror, because - in the style of the incredible Half-Life 2 - every cut scene unfolds through Tommy's eyes, and you can usually move around while you're watching events unfold or talking to people. Anyway, he comes back to the bar to find his grandfather waiting for him; Grandfather senses that a great change, and a great threat, is imminent. After wandering around the bar for a few minutes - you can even play arcade machines of Pac-Man, Hearts and Blackjack, and it's worth playing them for a while too… try it and see! - you talk with Jen and your grandfather, then two drunken thugs try it on with Jen and you're forced to beat them nearly to death with your trusty wrench, the melee weapon you always have to fall back on when all else fails.

It's after this little incident that all hell breaks loose, as well as the entire bar - a massive spaceship hovers overhead, pulling the bar into the air, piece by piece, along with Jen, your grandfather, and finally you. What follows is one of the most breathtaking introduction sequences to a game that I've ever witnessed, as the three of you are sealed into chambers that run along seemingly endless rails and you get a glimpse of what is to come - you see Earth in the distance, then you witness all manner of bizarre and grotesque alien life forms going about their routine business, as you trundle onwards to your inevitable doom. But what's this? There's a human with a strange accent on the loose, and he plants a bomb on a piece of equipment, which results in you being freed from your bonds. And so the game begins, as you start your epic journey through a living alien planetoid that has come to Earth to harvest its food and energy source - human beings.

While the premise behind Prey's story - that of aliens invading Earth for its resources - isn't original, its implementation certainly is. The story takes a backseat for most of the game, but it's always present and you're constantly intrigued to find out what's going to happen next. There's the matter of these strange humans, who don't look like they're actually from Earth and appear to have been on the planetoid for a long time, who you frequently see running around sabotaging things. Then there's the strange Judi Dench style female voice that echoes in your head every so often, the intelligence behind the alien menace, taunting you as you desperately try to rescue Jen. You also get to listen in to a few radio broadcasts that the planetoid has tuned into, where a talk show host is taking calls from people who are witnessing various strange phenomena occurring across America. While the aliens' intent seems relatively clear, there's a brilliant twist as to their true nature, and some very cool plot developments in the run up to the spectacular finale.

And spectacular is a word that can be used to describe the scale of the game - the levels are absolutely enormous and must span literally miles and miles, as you travel through the planetoid using various means. The graphics are very polished, running on the Doom 3 game engine, but with a distinctive next gen shine to them; there's simply no way this could have ever been developed for Xbox, and it shows. The biomechanical design of the planetoid is very cool and often very grim - there are sphincter-like vents that blow waste matter out like water from a whale's blowhole, grim looking tubes that lay egg sacs and organic flaps in the walls and floors, through which creatures can emerge and attack you, while many of the wall surfaces are pulsating and twitching. On the mechanical side, things are just as distinctive and original, with a very intricate and alien style to every aspect of the technology, from the display screens on the walls to the various touch screen panels you interact with, complete with alien writing. There is so much to see as you progress through the game, and so much variety, that it really shouldn't get repetitive - yet it does, at least a little.

The biggest problem with the game's setting is that it is quite gloomy, grim and depressing throughout, and so the brief excursions you take to the Cherokee spirit world come as a breath of fresh air - rolling mountains with a gorgeous blue sky - and the sunset near the end of the game is so beautiful that I just stopped on a cliff top and watched it for a few minutes. Anyway, while the game's designers have clearly gone to great lengths to keep things fresh throughout, it can feel like a bit of a slog at times, which is why I'd recommend that you stretch the fairly long single player campaign out a bit, and limit yourself to a couple of hours a day. It's hard to do that though, as you'll really want to find out what happens next, and it's difficult to tear yourself away!

If the gameplay was your standard Doom-style run and gun affair, then there's no doubt that the novelty would have worn off long before the end. However, there are so many unique, intelligent and ingeniously implemented original gameplay features in Prey that this simply isn't the case. For starters, not long into the game, after your grandfather is killed in a machine that's executing humans in a very disturbing way, you take your first visit to the spirit world, where your grandfather teaches you how to use your spirit form. From here onwards, you have a hawk companion (your spirit guide animal) who flies around, landing on switches that you need to use, as well as distracting and attacking enemies. But that's not the best part -you can have an out of body experience any time you like; hit the yellow button and Tommy's spirit stalks from his body, spirit bow in hand. Your spirit cannot be harmed by physical enemies, so not only does this make you a lethal hunter (although shots are limited, your spirit energy topped up by the spirits of fallen foes, which home in on you no matter how far away they are), but it leads to all manner of cool puzzles to solve.

The designers of this game are geniuses - they really are. Not since Halo have I seen a game that pushes the envelope in so many ways, and the amount of thought, effort and skill that must have gone into putting this game together simply defies belief. Every puzzle comes in the form of having to figure out how to progress through an area where an obstacle lies. For example, you might need to walk through a forcefield as a spirit so you can hit the deactivation switch on the other side. However, things get more complex than that, and soon you'll be leaving your body on a platform, then walking across a spirit path (the essence that remains where a physical walkway used to lie), to flick a switch that moves the platform that your body is still standing upon and helps you along your way. And that's just the tip of the iceberg.

Arguably even cooler than spirit walking is the gravity defying nature of Prey. Being inside an alien planetoid, gravity can be manipulated in various ways. There are energised paths that, when activated, have you walking up walls and along ceilings, while enemies beam in via portals below you, and you shoot them while upside down! Killing an enemy on a ceiling walkway and watching its body falling into the void below is incredibly satisfying, and although this can be disorientating at first, it's introduced in such a clever, gradual way that it soon becomes second nature, and soon you're negotiating all manner of moving platforms and sprawling walkway networks like it was perfectly normal. The other way in which gravity can be altered is in certain rooms where glowing panels are set on the walls, floor and ceiling. Simply shoot a panel and the room's gravity orientates accordingly - so shoot the wall and as the room spins you'll rotate to land on your feet, with gravity now turning the wall into the floor. It's such a superb effect, although it doesn't agree so well with Tommy!

The best feature of all though, for me at least, is the portals; two-dimensional circular gateways of energy open in front of you, or in a doorway, or even in a crate, through which you can see a completely different area of the planetoid. As you strafe back and forth in front of it, you'll see that behind the portal the room you're in is still there, yet look through it and there's a completely different room ahead of you! Walk around the back of the portal and you'll see that the scenery warps as you look through the shimmering air around it, then walk around the back and it's gone completely. It's just such an awesome effect! As well as using these portals to move around, they can also appear at any moment - and very often they do - to bring in a variety of gruesome aliens to fight off.

The alien designs in Prey are grotesque and very cool - kind of a like a collaboration between H. R. Giger and Clive Barker, so your worst nightmare multiplied by a factor of a hundred! You really hate these bastards, because of the horrible ways that they're mutilating and killing humans, which fuels your desire to kill every last one of the scumsuckers! Standard troopers are armed with rapid fire projectile weapons, then you have little two-legged dog things that run up and bite you, big Alien-style hunter dogs that charge at you and rip you to pieces, scuttling four-legged monsters with a humanoid upper body, full on human-alien hybrids that leap around swiping at you, and very grim human drones that have been violated and modified to be workers that maintain the planetoid's insides. There are others too - Matrix-style robots that speed through the air, firing volleys of shots at you, various floating monstrosities, and some big demon-esque bastards, giving you enough variety to keep your interest. They're intelligent too - sure, they attack you full on, but they do dodge your shots (or try to) and strafe around all over the place while shooting relentlessly.

So, you'll be needing a few weapons to take care of them - and these too are excellently conceived. Every weapon, bar your wrench, is of alien origin, and while they're mostly takes on standard FPS weapons, they are all extremely slick in their design. Your standard assault rifle type weapon has an organic eyepiece that stretches out and suckers over your eye (gross!) to become a powerful sniper weapon that can kill troopers with a single head shot, while grenades are scuttling three-legged crabs that you can set to either explode shortly after you throw them, or on proximity. Instead of a shotgun you have an acid-launcher with a superb vivid green splatter effect, and the rocket launcher fires those three-legged crabs, known as crawlers, at high velocity for a serious explosion on impact. The best weapon, though, is the leech gun, which sucks its ammo from energy pods that you'll find set into the walls at regular intervals. Best of all, there are four kinds - plasma, ice, electric and sun, each of which packs a serious punch and you'll soon find your favourites. Although the sun beam is fantastic, you don't get access to it until near the end of the game, so for me it's the one that blasts a powerful bolt of sparking electricity straight into your enemies like a rail gun, knocking them backwards on impact. Beautiful.

As if all this wasn't enough, you even get to fly at various points in the game, in shuttle suits that form around you, complete with a tractor beam and powerful rapid fire energy guns - these sections make a change from the on-foot action and feature some very cool moments, as you quickly navigate your way around large areas of the planetoid. There're just so many cool things to see in Prey, and more unusual and impressive visual effects than in any other game I've seen - you'll see huge machines with parts whirring around held only in place by unseen gravitational forces, then there's the shimmering of the portals, the bright, ethereal glowing effect of the spirit world when you leave your body, the unnervingly gross way that living doors squelch open, the way you can walk around small asteroids with their own gravity centre, rooms that form themselves before your very eyes, the hazy, shaking effect of the Keeper talking in your mind, the flickering glow of your cigarette lighter (replacing Doom's powerful torch beam), and much, much more. You'll even come across a commercial plane flying around the planetoid, oh, and the mutated spirits of dead children that attack you en masse - when you get to the part with the school bus, I guarantee you'll be freaked out!

Speaking of which, Prey has earned its 18 rating when you witness the gruesome state that many humans, including children, end up in, as well as the generally gory nature of the gunplay and the grotesque organic design of some of the scenery. There's also plenty of swearing - but you'd be using the f-word too, if you were trapped inside a giant alien planetoid that was harvesting the human race, being attacked on all sides by freaky mutant aliens who've kidnapped your girlfriend! The dialogue is very good, with excellent voice actors for all the characters, from Tommy, Jen and Grandfather to the Keeper, the radio host and the other incidental characters you meet along the way, as well as the random terrified humans, who you find quivering in a corner or see trundling along on those rails that you were previously trapped upon - including Jen, who always seems to be just out of your reach. As for the rest of the sound, it fits in with the gameplay perfectly, in an understated fashion - the weapons effects are very well done, as are ambient sounds of doors opening, footsteps on metal, forcefields humming and the various aliens growling and grunting as they fight you, then die. The music is also understated - there's a strong orchestral theme running throughout that's contemporary yet captures the feel of Native Americans very well, plus a cool little tune that plays when you're in your spirit form. Often there's no music at all, so when it does start to swell up dramatically it has all the more impact.

We all know that Prey is a single player game first and foremost, and the designers knew that too, as a bare bones multiplayer mode has been pretty much tacked on for a bit of extra lifespan. The sparse lobby, with only Deathmatch and Team Deathmatch modes available, and support for a maximum of eight players, is quite disappointing, as is the amount of lag you often get, especially with a full room, plus the amount of times you select a game only to find that you can't connect, or that it's already in progress. Still, it's not a huge problem and once you get into a good match without lag, you'll have a real blast. The gameplay is fast and frantic, just like Doom 3 multiplayer, but with the unusual weapon set, the added element of spirit walking and usage of gravity switches, portals, mini-planetoids and other gravity defying elements fully incorporated into each level, you'll find a set (albeit a small one of just eight) of maps that have been designed as cleverly as the main game. There are even two levels that feature shuttles, which is a very nice touch.

You would think that it's just a bit of throwaway fun, or a way to kill half an hour, but once you're online (enticed there by the gamer achievements, which for once are challenging yet realistically achievable), you'll find that it's extremely addictive and it's very easy for the hours to start slipping away. Voice support is there, and while you get your usual foul-mouthed jerks and cocky taunters (who I just love to blow away as much as possible!), I've also met some good, friendly folks on there who are willing to chat and banter as they play, having fun without taking it too seriously. Sure, it's competitive and everyone's doing their best, but it's always good to be in a room where people are joking around and not getting sore about losing or arrogant about kicking ass! The biggest drawback is the lack of interest in the 360 Live community - there are so very few games available and you often have to wait a while for a room to fill up, so it's best to play during America's evening time, which is late night for us, or at the weekend.

Prey isn't quite the groundbreaking Halo-beater we've all been waiting for (fingers crossed that Gears of War will be giving Halo a run for its money like we've all been hoping), but it's far more than just another Quake 4 type game. Absolutely every aspect of the gameplay design and presentation is simply dripping with quality - the look and feel is totally unique, and the altered gravity, portals, alien weapons and spirit walking all combine to create the finest 360 shooter since Perfect Dark Zero at the console's launch. It's not going to convert anyone to the genre, and despite the many cool elements it can at times still feel a little old school, but it's nevertheless one of the very best in its genre and a game that I Prey (sorry again!) attains the success that it so rightly deserves.

Reviewed by Geoff Holland for AceGamez (All Rights Reserved).