From the Horn Book, on The Golden Compass:
Indeed, the primary failing of this adaptation is its reductivity. Where the book was a series of questions, building upward, layer upon layer, the movie is all about the answers — starting with an opening-credits voiceover that explains many of the central truths of the trilogy, truths Pullman teased forth over the course of the whole story. Without those mysteries to draw viewers forward, the story seems merely to skate the surface (and while a shorter run time is usually indicative of responsible editing, here the film could really have borne expansion). In some ways the early explanations make the rest of the story more confusing, raising topics not explored until later volumes and eliminating, in the process, some brilliantly propulsive reveals.