Kate Beckinsale stated that after this movie's release, she was approached by a man in Paris, praising the movie, saying that he never saw the story of Hamlet work as a comedy. This movie was not meant to be a comedy.
The movie is a not a version of the Shakespeare's 'Hamlet'. It is the adaptation of an old Scandinavian legend (written down by medieval Danish historian) about the prince Amleth or Amlóði (which means "mad" in Old Norse) who pretend to be insane in order to get revenge. It is this plot Shakespeare borrowed from to create Hamlet.