I gave this film seven stars for the above average special effect they are using for an Asian movie. Normally, Asian movie are on pretty tight budget, I believe this movie received more investment than some others. The main actress is a singer turned actor, this is usually a disastrous move for western entertainment world but it does happen very often in Asian and she actually did a good job. Asian horror movies very frequently use young, innocent girl as main actress and she is perfect for that role. I must say, it works better than Western sexual appealing actresses. Most white girls are pretty tall and strong but with good body; I really think sometimes if they serious want to fight back, the bullies will get pounded.
Anyway, those young school girls and boys were as helpless as always but the only thing will work in this movie was their brain. Now another eastern culture people need to understand is that grades are everything; getting into good university is everything. There is something implied in the movie is about how those students were best students of the school and they have a bright future because they study hard and smart. Quite a few movies implies how stressful of the eastern education is and some writer thinks it is scary if he adds horror element on top of that stress will attract Audience. Based on the experience of the school in the UK, I really don't think English students will ever get it. Well, if you can think of it this way, you are fighting into the night after 1am in the morning trying to compete with one hundred thousands other students in the exam and there is a ghost start bothering you and try to rip your gut out, I think people will get disturbed by it.
By the way, I have seen way much more disturbing movies than it, so I am kinda numb. However, I thought among all the Korean horror movies, they do have some new ideas involving some psychological traps and supernatural activities. I liked the singer-actor small girl, it is refreshing to see a pure school girl for a change than teen-model wannabes getting slashed.
Worth a watch if you want to see something different. The movie is not that smart, direction was OK, story is fine if you are patient, please don't expect too much acting in a horror movie, in which I mean it is good enough. Try to get a friend grew up from Eastern Asian environment, you might enjoy this movie more if you know our culture.