Been playing Left 4 Dead 2 recently.
It's a first person shooter. You run around attempting to find supplies, guns and ammo while zombies try to murder you. It's been called an "interactive zombie movie" but I don't know if I'd take it that far. There's not a lot of plot or character development, although there is a rudimentary story and some funny dialogue.
The game itself, however, is fairly simple. You begin in one place. You equip yourself and fight a running battle to the end of the chapter, at which you reach a "safe room" where you barricade yourselves in and let the next chapter load. You "win" each section by making it to the "safe room" alive.
The first chapter of Left 4 Dead 2 opens on top of a hotel. The building is on fire. You've just missed the evac helicopter, and your only hope of survival is to escape the burning building and make it to a CEDA evacuation center at a nearby mall.
You can perhaps see where the problem here is. The "safe room" is in the lobby of the hotel. In short, you "win" the first chapter ... by barricading yourself into a room... in the lobby of a burning building.
Yeah, okay, perhaps "zombie movie" isn't bad. Better that than "interactive disaster trainer..."