Darren Carver-Balsiger’s review published on Letterboxd:
Decently made but nowhere near as competent as other Korean revenge thrillers. The main actors, Lee Byung-hun and Choi Min-sik, are both brilliant even if their characters are rather simplistic. The gore and violence is spectacular but might not be to everyone's liking. The film itself becomes repetitive once the revenge aspect kicks in and at least one fight between our main characters could have been removed. The film is definitely overlong and I found myself bored throughout most of the third act when the film became a simple good guy chasing bad guy scenario. The lack of nuance is a little disappointing as the film seems to not give us any reason to care about what happens to Choi Min-sik's psycho killer. Overall, I Saw the Devil is a heavy-handed film with little substance but it is well acted and kept me on the edge of my seat for the most part.