... at once political allegory and existential combat movie—Sartre's No Exit as directed by Sam Fuller.
Meanwhile, in the Goings on About Town blurbs in this week's New Yorker (it's easy to overlook, which is why no one seems to have mentioned this yet), David Denby says, more simply,
It’s Jean-Paul Sartre meets Sam Fuller.
No Exit, and its trapped scenario as microcosm of human existential despair, was surely an inevitable comparison; so too Fuller, for a movie compressing into 24 hours as much horrors-of-war iconography and archetypal-bordering-on-corny war-movie character types moral dilemmas as possible.
Or possibly all film critics just hang out in the lobby after screenings and plot the consensus in murmuring voices punctuated by sinister chuckles.