Steve G’s review published on Letterboxd :
I Saw the Devil is quite possibly one of the most ridiculous films that I've ever seen in my entire life.
Describing a film as such doesn't always mean you should avoid it like the clappers, of course. Many of the great action films especially are based on the most ludicrous of scenes and scenarios to keep the excitement ticking along. But I Saw The Devil isn't an action film and it absolutely does not need to be even half as completely lunatic as it is. If it just calmed down, it could easily have been a truly great film.
Yet, despite its excesses, it definitely should not be avoided. There is lots of good stuff in this tale about a Korean secret agent who sets out on an intricate and violent course of revenge against the serial killer who mutilated and murdered his pregnant wife, all the while placing the innocent and not-so-innocent in harm's way in his quest.
The base idea is good to a point. But it gets off to a pretty terrible start even beyond the secret agent revelation (I'm looking at the scene where they recover his wife's body - oh, COME ON!) that immediately says to you that you are not going to be getting a subtle unwinding of this tale at all, but more a totally insane and needlessly excessive unravelling of everything and everyone in it.
It is riddled with other problems, too. Apparently the characters in this film are actually from an alternate universe where they can be garotted, suffocated, have their faces battered repeatedly into rocks, be smacked repeatedly on the back of the head with hammers, clubs and crowbars, and they not only survive, but they are sometimes up and about and ready to go about their day within a couple of hours.
Then, on top of that, is the level of violence. It's almost as if director Jee-woon Kim is challenging himself at times to see the different ways he can hurt Min-sik Choi, who is actually brilliant as the stalked serial killer. I can hardly believe that this is the same guy who directed the fantastic A Tale Of Two Sisters, for the most part the very model of restraint and subtlety until it rightly and violently unravels in its last 20 minutes. I don't mind violence. I might wince at some of it, as I did here at times, but I don't mind it. But this film does not need to be nearly as violent as it is. At all.
Reigning in its excesses would have repaired some of the damage it does to itself, but its predictability, especially as it peters out towards the end, is perhaps a harder fix. Even so, despite the fact that it really is deeply flawed, it does have a lot going for it, too. The aforementioned performance aside, a couple of early scenes leading up to murders are very, very well done and very sinister indeed, and the entire scene of mayhem in the cannibal's house (just how many damn serial killers does this country have, by the way?) is thrilling and thoroughly exciting. I also appreciated the way the film manages to make us completely unsympathetic towards Byung-hun Lee as his reckless methods wipe out any feelings of sorrow we may have towards him for the loss of his wife.
So, I enjoyed some parts of it greatly. However, any film that causes me to throw my arms in the air and exclaim, "Oh, fuck OFF!" after the latest character battering that doesn't lead to a death is one that really, really has its problems. You have to see it, though. There's a good chance you will adore it. It's quite mad, you know.