I hadn't heard about this film but decided to indulge as the premise seemed interesting. Well, who doesn't like the story of a mutant.
But don't be confused and don't take this as a sci-fi. The story is about Park Goo who starts mutating into a fish after he volunteers for a drug trial. That's the only part closer to science as the whole movie deals with his struggle and various people who are trying to help him for different reasons.
The film though a bit slow focuses on a some very important issues and raises some valid questions. It shows how an event which is about to nearly destroy the normal life known to one is turned into something political and financial by the system. It is shown beautifully how people sympathies with the "fish man" and treat him as a reflection of their problems on one side while others are ready to utilize him for their political of financial gain.
Lee Kwang-Soo playing the fish man appears under a mask for most of the time and we seldom see his face. He still gives a convincing performance and his low, timid voice is enough to let you know what kind of pain he is in.
The supporting cast is good too. Joo-Jin and Sang-Won do a brilliant job shifting their character from one shade to another. And, Jang Gwang too plays the part the of a shaken and disturbed father to excellence.
Overall I liked the film for what it was and what it wanted to say. It might seem a bit slow to some but the director does a good job to keep in under 93 mins.
Do give this a viewing as it has a lot of soul and a brilliant story to tell which is highly relevant to the system we abide to.