Manga was OK... I liked it.
Movie was awesome... I loved it.
Novel is as awesome as the movie... or maybe even more. The movie and the novel complement each other; one for the visual, and the other for the background history.
42 students that enter in the Program, only 1 can survive. There may be too many students, but we get to know each one of them. I loved that; that they are not random characters that kill and get killed. And each kill was.. WOW. So gore, so violent and all different from each other.
Not only Shuya is the MC, but Noriko, Shogo [(although I knew beforehand of his death, I was in denial.. why did he have to die? He was a great character )], Shinji as well... The death of the girls are so memorable (Takako's, the girls at the lighthouse...) WOW
I may say that the only tiny thing I liked better in the movie is Sakamochi. In the novel, he is a crazy, sadistic, rapist psycho (just like in the manga). In the movie, he (at least that we know of), does not rape anyone.
Excellent book, that does not get lost in translation at all