“Visible, violent death” is the buzz phrase for Warhammer 40,000: Space Marine and from the moment we pick up the controller for a hands-on with four carefully selected sections from the game, it's immediately evident why. There's loads of visible, violent death, believe it or not and most of it involves green Ork flesh being transformed into crimson purée with a chainsword and a bolter pistol. You're seven-foot tall, 1000lb man-mountain Captain Titus, leader of the Ultramarines with nineteen additional transplanted organs, thick power armour and an insatiable thirst for battle. As such, you're a fighting machine for the Imperium, genetically built for war and packing chunky guns and a rasping chainsword that you're able to seamlessly switch between in a scrap.

With mankind teetering on the edge of extinction and the Orks invading one of the Imperium's valuable Forge World's for its Titan war machines, it's up to Titus and his legion of Ultramarines to stem the Ork threat and save the Forge World from falling into the hands of the unhinged, bloodthirsty and tribal greenskins. Along the way, you'll also encounter the forces of Chaos; fallen space marines who have submitted to darkness, transforming them into powerful, dark and twisted creatures that are a space marine's worst nightmare. That said, it's hard to be scared when you're an immovable lump that can decimate entire armies with ruthless efficiency.

There's no cover system to cower behind in Space Marine, as you're essentially a heavily armoured tank, so you're rewarded for getting stuck in and getting your hands dirty. Keeping your health bar up and your fury meter ticking over requires mixing it up with your enemies, carving into waves of Orks with your chainsword, which is capable of both quicker light attacks with X or heavier attacks with Y. With the light attacks, stringing a fast four-hit combo together is easy, but in the frenzy of a heated skirmish, you can sometimes find that Titus - who is supposed to be a 150 year veteran in fighting for the Imperium – ends up swinging his melee weapon at nothing, which just seems plain wrong. Still, nine times out of ten at least, Titus connects with his intended target and with each bludgeoned Ork, comes another boost to your fury gauge.

Hold Y and you can let rip with a fury attack once the meter is filled, tearing through a whole swathe of enemies if used in the right place at the right moment. Engaging in melee is nice and responsive, as is switching between your ranged and melee attacks. You can even line up a ranged fury attack with B and hitting the same button at close-quarters initiates a cinematic, instant sync kill, which is a gloriously brutal and up-close execution move best reserved for the tougher enemy units. Our hands-on session presents plenty of opportunity to experiment with each of these combat mechanics, as well as giving us a good overview of the game's jaw-dropping vistas that include a towering crane stretching across the horizon, intricate, imposing architecture and towering Gothic spires piercing the dark skies. Sometimes, you just have to stop and rotate the camera, just to simply take in and absorb the epic views on offer.

Our hands-on with pre-alpha code, first takes us underground when a bridge collapse beneath Titus's heavy boots, leading into a viper's nest of Orks. The greenskins come in all shapes and sizes, from the diminutive, expendable Gretchin to the tougher 'Ard Boy and Melee Nob. Sometimes, you'll encounter the Ranged Boy and Ranged Nob, and these really need to be taken out first, which is where the ability to wield your gun and melee weapon in tandem, really comes into its own. Pressing through the Orks, we emerge outside to the sight of the aforementioned crane, before brawling our way through even more Orks to find a switch that need to be thrown to drop the crane's payload of a giant cannon on a group of enemies in the distance. The ensuing destruction on the horizon is mighty satisfying, and then we move on to the next section, where we have the assistance of two fellow Ultramarines.

Besieged by a far greater number of Orks, it can be easy to get pinned in one spot, and as Titus's shield, health and fury gauge only replenish when you take the fight to your enemies, you can occasionally get a bit carried away and end up dying suddenly. Your AI partners aren't really a huge help in battle, so it ultimately falls to you to clear a path and when the ranged enemies start popping you from a distance, the fast pace and momentum of the gameplay evident elsewhere can be slowed to a halt while you carefully pick off distant foes. During the final section of our hands-on demo in a canyon, we encounter Chaos Bloodletter Daemons who are dangerously swift and deadly, making shots with the sticky grenade launcher, the plasma gun or the bolter at range a sound strategy. Titus can also hurl a grenade into groups and as we stumble upon a scuffle between the forces of Chaos and some Orks, a well-placed explosive is just the ticket.

Pressing on down the canyon, we're ambushed by Renegade Guards, more Bloodletters and a Psyker who is summoning a portal for more Chaos to emerge into the region. Using the Stalker-Pattern Bolter with its scope, we attempt to do some sniping, but bagging a satisfying headshot is almost impossible in this particular situation. After multiple deaths and retries, we manage to kill the Psyker to close the portal and execute the last of the Bloodletters and Renegades on the flanking precipices of the canyon edge. It just goes to show that Space Marine will still be suitably challenging, so tightening up the shooter mechanics will go a long way towards making the game feel more robust and gratifying.

Overall, Space Marine feels chunky and solid, and if Relic can simply tighten up the combat just a little bit more, then its sure to be onto a winner. There's no issue with the responsiveness and the seamless switching between melee and ranged weapons, but swinging at thin air and some fairly woolly sniping need to be addressed between now and the game's launch this summer. Space Marine looks undeniably stunning and the environments are outstanding. If Relic can deliver on the promise of its combat mechanics, then we could be looking at a third-person action blockbuster.

Warhammer 40,000: Space Marine is scheduled to launch in August 2011.