Few next-gen games have got us as excited as Ubisoft Montreal's Far Cry 2. Having seen the game numerous times over the last year the prospect of getting our hands on a near-complete build of the Xbox 360 game for an uninterrupted gaming session was something we simply couldn't refuse. We headed into the free-roaming African environment to see if this ambitious FPS has what it takes to compete with current large-scale FPS king Crysis and switched off our Xbox 360 hours later desperate to get our hands on the final game.

After choosing one of nine playable characters (we chose Josip Idromeno, a 48-year-old Albanian and ex-paratrooper and bodyguard) we were introduced to the game via an impressive cab journey, with our guide giving us a rough outline of the political climate and an overview of what's going on. We took the opportunity to have a look around from the backseat, taking in the glorious views, spotting a plane taking off and watching as a cattle farmer herded his animals across the road.

More than anything else this intro demonstrated the sheer size of the game. The cab driver took a pretty direct route to our destination, but even so it took a fair few minutes to get there. It also showed that movement from place to place isn't going to be easy. We passed through a heavily guarded check point that required some sweet talking and a bribe from our cabbie. Anyway, as interesting and beautiful as this journey was, we wanted action and it wasn't far away.

We don't want to spoil too much of the opening so we'll just say that our first fire-fight came after an explosion caused us to run from a building. We capped a guy in the head with our pistol and grabbed his automatic weapon. Explosions were ringing in our ears and bullets were being sprayed from one end of a road to the other. A war had broken out between the United Front for Liberation and Labour (UFLL) and Alliance for Popular Resistance (APR) - the two rival factions in the game - and we were right in the middle of it. A Jeep full of soldiers pulled up, only to go spiralling into the air in a ball of flames moments later. Taking this opportunity we ran as fast as we could away from the action, but it was no use. A few shots in the back and we were eating dirt, although thankfully help was on hand and we were whisked away to safety.

The game is massive and surprisingly full of variety

Far Cry 2 revolves around the two warring factions and an arms dealer known as the Jackal. The Jackal is supplying weapons to both factions, effectively fuelling the war and profiting from both parties. Your task is to take him out, denting the war effort on both sides and hopefully bringing an end to it completely. Of course, this won't be easy, so you'll spend an awful lot of time taking missions for each faction as you gradually home in on your target. It's how these missions work and the open nature of the environment that looks to separate Far Cry 2 from its FPS competitors.

Missions are handed out by factions and by arms dealers. Faction missions curry favour with the factions and earn you some much needed diamonds (the game's currency), while arms dealer missions give you access to new weapons, purchasable from a computer terminal. Missions themselves aren't especially different to those seen in other games (kill so and so, get some intelligence info from someone, etc) but the way you approach each can vary quite drastically. Your incredibly handy map shows all routes to your objective as well as any locations you've marked by using your monocular - such as sniper positions and ammo crates - giving you a tactical advantage.

The game engine is a thing of beauty

Missions in Far Cry 2 don't take place in enclosed worlds, so you're free to approach them from any angle, on foot or in a vehicle, armed with a rocket launcher, sniper rifle or machine gun, or simply a machete for stealth kills. The choice is yours, and this is further emphasised by the way NPCs change the way they behave at night. Far Cry 2 features a full 24-hour day/night cycle (which you can advance to a certain time by sleeping in a safe house), so if you want to play a mission using stealth you can sleep until its midnight. If you're going in all guns blazing and don't want to be caught off-guard by an enemy lurking in the shadows, head in at noon. We replayed one of the early missions numerous ways and each time the mission felt very different.

Combat so far seems to be action packed and pretty intense, with enemies demonstrating impressive AI and chasing us across the map in their Jeeps. Your character can only carry four weapons at once, with one slot being taken up by a machete, so it pays to plan ahead. You're allowed one weapon from each of the three categories: primary, secondary and special. Primary weapons include sniper rifles, assault rifles and shotguns; secondary weapons include pistols, machine pistols and one-handed weapons; and special weapons include rocket launchers, flame throwers and other unique items you'll come across throughout the game.

Weapons from dealers are in perfect condition, but anything you pick up from a downed enemy won't be and could jam on you during combat, or fail to work altogether. You'll be able to tell how much of a state a weapon is in by looking at it, with rust and wear and tear being clearly visible. Dealerships will also allow you to upgrade weapons, although this will come at a price.

As well as the various guns the game has to offer, you'll also be able to carry grenades and Molotov cocktails, ideal for blowing up Jeeps full of enemies or for setting fire to the long grass. We know we're in a time where saving the planet is an extremely hot topic, but watching a fire spread from an accidentally exploded Jeep, to some tall grass and then a clump of trees is incredibly satisfying and a great demonstration of next-gen technology. The way the smoke blows across the sky in the direction of the wind is a nice touch too. While we're on the subject of nice touches, the weather system in Far Cry 2 is stunning to see in action. Trees blow, rain pours and it verges on looking real. The Xbox 360 version we tested looks great, although we expect the PC game will have the edge when running on a high-end PC.

Enemies aren't the only danger in Far Cry 2, with your character suffering from Malaria. From time to time you'll get weak and require a tablet so you'll need to do favours for people in order to get hold of them. Staying in good health is a key component of the game, with your character able to dig out bullets using tweezers and perform various other minor, but rather gruesome, medical procedures. These help sustain your health but you'll need to inject yourself with a syringe in order to have a fully replenished health bar. This makes for combat that feels similar to DICE's Battlefield Bad Company, although Far Cry 2 seems to be the harder game.

You'll be able to travel by land, sea and air.

One unique aspect of the game that we've yet to fully experience is the buddy system. Throughout the game you can essentially befriend NPCs who will then offer you assistance during combat (bringing you back from near death situations) and give you alternate ways to tackle missions. One of the early missions in the game required us to take out a group of NPCs and one of our buddies gave us a way to get them to relocate to a more vulnerable position. We ignored it, choosing to go in all guns blazing with a grenade launcher, but the offer was there if we wanted it. We're hopeful that buddies will play an important part in the game and offer plenty of help during missions. We've also only really dabbled with the vehicles in the game, sticking mainly to the banged out motor we started the game with. Although very different games in tone and style, a comparison to GTA4 can definitely be made.

With Far Cry 2 set for release on PC, Xbox 360 and PlayStation 3 on October 24 (the day our pockets, piggy banks and savings accounts are dreading) we can't wait to see how the final game plays out over what looks set to be a fairly enormous campaign that stretches over 50 km2 of land. We can't be certain, given that we've only sampled a fraction of what Ubisoft Montreal has created, but if we were betting men we'd put money on Far Cry 2 being one of the best first-person shooters of the year.

Far Cry 2 is due for release in Europe for PC, Xbox 360 and PlayStation 3 on October 24.