Richard "Dick" Marcinko, alias Demo Dick, alias Shark Man of the Delta, alias Rogue Warrior, is something of a military legend. During the Vietnam war he won four bronze stars and the Vietnamese Gallantry Cross, as well as picking up a bounty on his head from the Vietcong. In 1980 he helped to set up the US Navy Seals' first ever counter-terrorist unit: at the time there were only two SEAL units in existence, but they called the new group SEAL Team Six just to confuse the Ruskies. He then went to set up a specialist unit called Red Cell, designed to test America's own defensive forces. Dick broke into military, sneaked onto nuclear submarines - he even crept aboard Air Force One. He eventually served as a technical advisor to the makers of 24, which was fairly appropriate given that this man was the original, real-life Jack Bauer.

And now Demo Dick is getting his own game - a sweary first-person shooter with minor stealth elements and lots of extremely violent hand-to-hand executions; it's also got Mickey Rourke providing the gravelly voice of Dick himself. The story is set during the 1980s and seems to be an amalgamation of every straight-to-video action film you've ever seen, plus a dollop of Marcinko's own experiences (Apparently even Dick himself is happy to admit that his book of memoirs, also named Rogue Warrior, is more than a little "flexible" with the truth).

Still, a little bit of excess never hurt anyone - and there was something undeniably enjoyable about the ludicrous action shown off at Bethesda's showcase last week. Our demo found Dick attempting to destroy some anti ballistic missiles at a compound on the border between Russia and Korea. This mission provided an opportunity to witness Rogue Warrior's two main flavours of gameplay, infiltration and assault, as well as the game's gleeful hunger for violence.

This last quality was evident within seconds of the demo starting. To the sounds of a gloriously cheesy 80's soundtrack, Dick sneaked into the enemy base and started shuffling the bad guys off of their mortal coil. For the majority of the time the game is viewed from a first-person perspective, but when you're creeping about in cover the game switches to an external view. By getting up close to a hostile soldier you'll be able to trigger a context-sensitive Kill Move at the touch of a button. "Rest in piece, asshole!" cried Dick as he pushed one hapless guard over the edge of a bridge. Other Kill Moves proved even more wince-inducing: Dick grabs the enemy's gun and forces it up under their chin before putting a bullet in their brain; Dick slashes a man's neck and then pushes them to the floor so he can open up the wound; Dick stabs someone in the eye. "Dick has seen these Kill Moves," says Sean Griffiths, senior producer at Rebellion. "He wholeheartedly approves of them. They are methods that he has used out in the field."

Will there be a Demo Dick demo?

Aside from these extremely violent executions - all 25 of them - and his vicious selection of taunts ("April Fool, Motherf**ker!"), Dick also can also do sneaky things like shooting out lights and blowing up fuse boxes to plunge his opponents into darkness. Naturally enough, the quiet approach doesn't last long though. Every mission will have a moment where all-out assault becomes inevitable, and the demo assignment was no exception; Dick appeared to have cleared out the building he was in when suddenly a group of Spetsnaz fighters came crashing through the roof. "As Dick would say, this is a total goatf**k now!" exclaimed Griffiths. Quite.

With stealth all but abandoned, the demo mission headed for familiar FPS territory as Dick exploded and head-shotted his way out of the military base. To be honest, the only feature of the game that seems like a genuine departure from convention was the audio presence of Mickey Rourke, grunting and swearing in response to each and every round that headed his way. As amusing as his outbursts are (and they most certainly are, if you're a puerile chap like myself), the game will need something more if it's to make a name for itself. No-one would ever accuse Rogue Warrior of being eye candy, and to be honest at times the game looked like something you'd expect from a previous generation. Aside from the personality of Dick himself, and the admittedly impressive participation of Mr Rourke, it's hard to see how this game will ever compete against the likes of the forthcoming Modern Warfare 2.

The game's not finished yet, of course. The build we were shown was only pre-alpha code, so perhaps Rogue Warrior will receive a bit of a makeover between here and release. Still, better graphics won't help with the fact that it all seems extremely generic at the moment. This project has actually been around for a long time (three years at least) and went through a redesign after the developers decided they weren't happy with the way it was going. In short, if they were going to put in new ideas they probably would have implemented them by now. On the plus-side, the final product will have a multiplayer mode that allows you to pull off Kill Moves on up to 15 of your friends. We're also informed that, "the best player will get the Dick skin" - a prize that's probably less unpleasant than it sounds. As always, we'll hold back our full judgement until we've seen the final product, but if it's not up to scratch we wouldn't want to be in Rebellion's shoes. After all, Dick once killed a man using nothing more than a Russian toilet-roll holder; he's probably not the kind of guy you want to piss off - even at the age of 68.

Rogue Warrior will released on PC, PS3 and Xbox 360 during Q4 2009.