CARRiON-XCII: Apocalypse Now felt less like a Vietnam war movie and more like a psychological horror that showcases a loss of one's humanity and a breakdown of one's reality.
Gotta agree. The war (or this particular war) is just a backdrop, must be the reason why its one of my favourite movies while i generally dont like war movies ;)
At topic: dont really see how this would work either. There wasnt a whole lot of fighting in the movie, it was more of a road (river...) trip that got more and more surreal, dunno what kind of gameplay would fit...
Spec Ops the line comes to mind, which was very obviously inspired by AN but the over the top shooting kinda distracted from the serious elements in my opinion.