The press synopsis calls this a "wickedly fun horror-thriller." I have to agree as I watch a punk rock band try to flee the scene of horrific violence only to land in a desperate fight for survival with some white-supremacy skinheads. This is done in the same spirit as "Tucker and Dale vs Evil," only with not as much humor...smile... By the way, a green room is a place where performers wait before and after an appearance. In this movie, our eponymous room is, in turns, a waiting room, a prison and a sanctuary.
This R-rated actioner, written and directed by Jeremy Saultnier ("Blue Ruin") had our packed-house screening audience on the edge of our seats, holding our collective breath even as we laughed at the lengths our frantic heroes go to in order to survive. They aren't always successful...
Expect profanity plus gruesome violence with guns, knives, fluorescent light bulbs, metal rods, attack dogs, and deadliest of all, a utility knife. At no time do we see those people on screen as anything less than real flesh and blood who can be mutilated, gutted or killed. I was exhausted when it was over.