I thought this will be another run of the mill slasher gore-fest flick where stupid kids die one by one, but was pleasantly surprised to see the execution. I mean the story is what you'd expect from such film, and the basic formula is similar, but the way they presented and flowed it was somewhat refreshing. The flow of the movie was its defining part for me. It felt natural, giving the situation a realistic feel and creating an ever present feel of tension when things go down.
The movie wasn't super violent or gore-y just for the sake of it either. It was a bit tamed, and the way violence was presented made you feel uneasy, like it should. And being named as 'Green Room', there was an overall green tint in the visuals, a nice touch.
Some of the acting was really good, like from Anton Yelchin (Rest in Peace) and Imogen Poots, AND of course Patrick Stewart as the main villain. Wish he had more scenes being all evil and stuff.
But some of the other cast wasn't always good. And of course, character make stupid decisions, some that feel fine considering the situation while some were just plain dumb. And with the movie focusing on providing realism, there were scenes which felt totally off from it, breaking the immersion and tension and taking me out of the movie for that duration, which is a shame as if those scenes weren't present, this could have been a solid great watch.
Still, it is enjoyable nonetheless. And if you are into these types of movies, then I definitely recommend it.