Nothing special

Rating: Null/10 (4 January 2011)

The writers at least understood how horror films work. They avoided jump "scares", relying instead on actual atmosphere (at first). The gore isn't really for gore's sake and seems intended to shock people with the depravity of the acts, since many violent acts are shown after the fact.
Additionally if the writers didn't have the sense to leave it ambiguous, it missed any real explanation, as the only reference about "Hell" seems to be a translation from one recorded message, hence more along the lines of a character's perception.
They didn't entirely avoid tripping themselves up. The atmosphere while creepy initially is interrupted by a special effects sequence; granted, for plot reasons but still preventing the movie from being effective. Cooper's "humor" was annoying, it wasn't funny at all.