Knight's film is one of those cinematic high-wire acts in the vein of "Buried" and "All is Lost" in which a director tries to burnish his storytelling cred by tying one hand behind his back and setting his whole film in one place.
It's the type of concept similar to what Rodrigo Cortes was going for in " Buried ."
Think Castaway with Tom Hanks (2000), Buried with Ryan Reynolds (2010), 127 Hours with James Franco (2010) and last year's Gravity (Sandra Bullock) and All is Lost (Robert Redford).
Dramatic stuff to be sure, though far removed from the sort of nail-biting thriller narrative audiences have come to expect from the man-in-a-confined-space sub-genre (think: Ryan Reynolds in Buried, Colin Farrell in Phone Booth, etc.).
Most man-in-a-can titles wear out their welcome quickly, including “ Phone Booth ,” about a man trapped in you know what, and “ Buried ,” about a far less lucky guy buried alive in a coffin; in “Gravity,” Sandra Bullock switched cans often enough that the movie never felt oppressive.