There has recently been a highly acclaimed adaptation of HP Lovecraft's novel, The Call of Cthulhu. I'm very interested in this movie as I've loved the novel, but I wondered how closely this movie stuck to the novel's story and style?
Movie and novel are fairly close: both keep to the same "frame story" style (story within a story within a story) with German Expressionism as a movie tool to replace Lovecraft original writing style (so you have actors overacting emotions when they encounter "blasphemous, cyclopean, unnamed shapes that could not exist!").
Story in both cases is almost identical with few differences:
The sailors aboard the Emma first encounter the Alert abandoned at sea, rather than crewed by Cthulhu cultists and taken over by Emma's crew after a violent confrontation as in the original story. Additionally, the film depicts the narrator present at the time of his great-uncle's death, who dies peacefully in his sleep, rather than being summoned upon the mysterious death of his great-uncle, who was presumably killed by Cthulhu cultists in the original short story. The narrator (Matt Foyer) notes that Inspector Legrasse, who had directed the raid on cultists in backwoods Louisiana, died before the narrator's investigation began.
In the original story, the narrator does not seem to end in a lunatic asylum or experience any mysterious nightmares himself. source
It doesn't, really. As with most adaptations of Lovecraft, what makes a good screenplay is also NOT what makes an HP Lovecraft story. It doesn't seem at all like the story, I didn't even see the scene where they were rolling dice and noticed boxcars every time. They are different stories altogether.