I just don't get movies like this. Why make a movie based on a certain thing and then have such utter disrespect for that certain thing. Junji Ito is by far one of my favorite authors, and while Gyo is far from his best work it still was pretty good. It was Ito doing what he does best. Evoke an otherworldly feeling of terror and mixing that up with bizarre imagery.
While this movie has some elements from the manga it completely lacks the essence. The world wide chaos is somewhat there and some of the imagery really lives up to the manga. But for the most part I just get the feeling this is based on a badly told resume rather than the manga itself. Characthers that where not even in the manga are added. Now that wouldn't be a problem if they actually did something useful to flesh out the story, but no. They are a complete waste of space. Only there to fill out key elements of the manga where they didn't belong in the first place.
The characters that was in the manga are completely altered beyond recognition. Kaori and Tadashi even switch places in the chain of events that took place in the manga. Important pieces of the story are breezed over or just omitted. The sheer incompetence at work here just astounds me. As an adaption this fails miserably. Maybe you can enjoy it if you haven't read the manga. But as one who have I must say this one was just painful to watch. Some credit must be given to the animation witch at times is really great, apart from the cgi. I never was a fan of 3d animation.
The sense of total despair and hopelessness as the army of fish is slowly taking over human territory is there. I just wish they could have at least tried to follow the manga better. A total waste of time if you have read the source material. I give it 2/10 and that's being generous.