Time Out says
Cults figure twofold in Philip Ridley's story of a Londoner (Sturgess) who's self-consciously battling his demons. As in, he's fighting an actual epidemic of creatures from Hell, with lizardlike faces and a penchant for baggy hoodies. (Imagine a basilisk crossed with Banksy.) This gang of netherthugs who hail the Dark Lord is only the second-scariest group connected to this horror film, however. The first would be the rabid Ridley fanatics who worship the fantasy writer's prolific work and view his two features---1990's The Reflecting Skin and 1995's The Passion of Darkly Noon---as the ultimate in Southern Gothic--flavored spookiness. They, and only they, may lap up Ridley's notions about urban youth run amok, and forgive the way this movie clumsily switches gears into Faust territory.
That's right: After being summoned to meet Satan via smartphone (memo to self: cancel my Beelzebub-friendly plan with Verizon), our hero makes a deal with the devil (Mawle) to erase his facial birthmark, in order to get it on with an Eastern European model (Posy). We know how these bargains turn out, so all we're left to do is watch pretentious exchanges about grief pile up, laugh at the way the movie exploits its Indian-girl-as-innocence-personified notion and wish that Eddie Marsan's giddy cameo as Hell's personal weapons dealer were much, much longer.
Watch the trailer