One Man Army

During my college and university years, I watched a lot a movies - in particular I was struck by the 'one man army' genre of action movie. You know the kind: One guy is up against a whole horde of baddies and spends the entire length of the movie taking them all out one by one.
Indeed, such is the strength of the concept that it has since provided the basis for many action games.

But here's something I've been pondering on for quite some time: In regards to this one-man-army scenario, what exactly is the correlation between action and motivation? Killing a bunch of guys by yourself is a mammoth undertaking - more so if the guys in question own and operate some kind of organization/corporation. To do so would take a motivation worth seeing through to the end.

That being said, I have, for the longest time, wanted to see someone take this formula and turn it on it's head. How about a one-man-army where the protagonist is someone who blundered his way into this mess by accident? And has to fight for his life against foes who are equally confused by his presence as he is? Or how about where the protagonist is someone who is doing this undertaking for something so, by comparison, small and insignificant?

Such scenarios have potential and I would like to see one played out - and what do you know I can see glimpses in he games I've played. When I was playing Bioshock I could see the scenario being put to use as the player controls an interloper to the city of Rapture and Andrew Ryan, through his video logs, is baffled as to who the player character is and what he's doing there. This set up is of course ruined with the confrontation with Andrew Ryan but then again 2K had their own story to tell but for me it's still a missed opportunity. How could it be for an average shlub to accidentally stumble across Rapture and explore it...only to have them fight for their life against a foe who's mistaking him for the CIA or some other organization?
As for the second scenario I can see traces of it in the Nuevo Paraiso portion of Red Dead Redemption. Throughout the portion John Marston gets caught up in a conflict against a corrupt president and idealistic revolutionary. Eventually Marston must pick a side and take part in the subsequent revolution. But it is interesting to note that all Marston wants is the location of Javier Escuella and Bill Williamson - thus Marston ends up doing odd jobs for the two opposing sides on the promise of telling where these men are. But most of the promises don't come through much to Marston's increasing annoyance. Thus there is something somewhat evocative with when the revolution comes and Marston is reacting to the mayhem around him by shouting: "WHERE'S JAVIER ESCUELLA?!?!?!?"

But in the end these examples are just fleeting glimpses - all it need is someone to take the first full step. And when I think about it, it is rather puzzling why this hasn't caught on seeing that video games rely on the 'one man army' concept and even cases of 'Who needs motivation when there are dudes to shoot.' I figured the scenarios I mentioned be more akin to a natural fit.
Still at least it's a start....