I’ve never read the comic book, though the only people who have provided bad reviews (primarily with the ending of the movie) are those who have read the comic book.
Aside from the ending, they have good things to say.
Via The Guardian…
Pundits have been impressed by the film’s detailed canvas, its adherence to the storyline followed by the original comic – which centers on a world threatened with imminent nuclear apocalypse – and its refusal to stint on scenes of a sexual or violent nature. This is an 18-rated superhero movie which makes last year’s famously brooding Batman sequel The Dark Knight look like Alvin and the Chipmunks.
