Homefront is Kaos Studios' second entry into the crowded FPS genre, their first being 2008's Frontlines: Fuel of War. Both games are set in a possible near-future war, with Frontlines' conflict based around the inevitable exhaustion of the world's oil supplies and Homefront exploring the possibility of an aggressively expanding North Korea.
Homefront's singleplayer campaign takes place as the western half of America has been occupied for a few years by an army from North Korea. The living conditions for the average American are pretty grim. Either they eke out a living on their own among the shattered remnants of their cities, or more likely they are conscripted into forced labour crews, toiling endlessly for the occupying forces.
As the game gets underway this seems to be the fate that has found you. You've been rounded up by the Korean People's Army - the KPA or "norks" - along with some other poor unfortunates and shepherded onto a converted school bus. It emerges that this group consists of people with some level of flight experience, with the assumption you're to be put to work. After some "re-education", of course.
As the bus winds through the streets of a shattered American town you look out to see KPA troops harassing civilians, arresting them in some instances, beating them with boots and rifle butts in others. As one runs away from the troops he is, quite casually, shot in the back of the head, leaving a wet splatter of blood on the window ahead of you.
If that's a little too grim for you, this is the point you should stop playing. Because the game goes to much darker places than this before the end.