I'm really amazed and impressed with the consistency and the quality of many of the Korean films that I've seen. I'm no expert, that's for sure, but you can tell that they really put a LOT of effort into creating an excellent, involving story. The acting, alone, is WAY above the average American film (and I happen to have been raised by and live near San Diego :)
This primarily is a Police Procedural about a father looking for his kidnapped child, but it has some nice, low-key, Science Fiction touches that are integral to the story. You can likely guess what some of these are by the title of the film. But, what I was most impressed by was just how well done the movie was. It honestly kept me in suspense and did an excellent job in maintaining that tension throughout the entire film.
I read one external review where they dismissed this movie as a poor copy of another really well known (and quite excellent) film. I won't mention the title of it because I don't want to give too much away. But, I very much disagree with that reviewer because as masterful and stunning as the other film is that he was referring too, I truly feel that a movie should be judged on it's own as to how well it is put together and based upon the quality of it's story, direction, acting, etc. And, this one I felt was actually quite good. It's not a Sci Fi Blockbuster by any means, so please don't expect 'TRANSFORMERS'-like effects and such. No, this is mainly a powerful Police Drama along with an excellent Mystery as to what has happened to the child. Add in the nice Sci Fi elements that propel the story and I feel that you have a very entertaining movie that does an excellent job in involving the audience in not only the search for the man's son, but also the intriguing twists and turns that reveal themselves as time goes on.
If you like a good Police Drama Thriller and also enjoy some light Sci Fi elements woven into the story, I think that there is a good chance that you might enjoy this film.
Review by lathe-of-heaven from the Internet Movie Database.