I saw the film yesterday as I'm currently in Seoul, South Korea and the movie has already opened here! I've never read the comic book, so I can't compare, but I think most people will be satisfied with the movie. I agree that it made me want to know more about the comic. The Korean audience seemed to enjoy it as well. The visual look of the movie is great, especially the scenes set in Hell. The script had a few slack points but was fairly intelligent and depicted Constantine as an ambivalent and fairly dark character. As a former theological student, I thought the movie had a fairly interesting worldview that probably came directly from the comic. The acting was solid, including Keanu, who actually hasn't given a really terrible performance in years and should be cut some slack. I especially liked Tilda Swinton as the androgynous Gabriel.