It's a bit of "Home Alone" with zombies. Almost the entire film happened in one location (Joon-woo's apartment), and we get a sense of how lonely it was for him. My eyes were glued to the screen watching this. The introduction of the character Yoo-bin brought a breath of fresh air into the film, and the interaction between the two was great to watch. I don't think there's anything new in this film though, as this is very similar to a French zombie film “The Night Eats the World", but it's still very gripping in its execution that you can't help but grip the edge of your seat while watching this. Effective use of moments of silence, dark environments, narrow hallways as well as the building's setup. It was a great watch.