Its places you into the action right from the beginning and takes you on a journey that is full tilt from start to finish. I was lucky to see this in a cinema in New Zealand so if you can see it on the big screen I recommend you do so, its certainly just that much more immersive and impressive surrounded by a sea of strangers. There's some powerhouse performances from all the leads, I love Lee Do Hyun, so him and the subject matter was what drew me to the film. I think for me the only downside was this story seems like it could have been fleshed out more in a series rather then a movie, it felt like it was wrapped up too quickly for me at least. They hinted at the background of the main characters but you never felt completely invested in the horror they were facing because you weren't given enough information about them. The soundtrack is masterful and the cinematography sublime. I still very much recommend this film.