This movie left out some very important aspects of this story. It relied too heavily on viewers having read the book. Important issues such as the focus and wonderment of the potions book that belonged to the Half Blood prince, Draco's reasons for being so upset that he vomited in the bathroom, the full reasons for the unbreakable vow, and the inaccuarcies surrounding Dumbledores death, no fighting shown in the castle, etc.... too much was taken for granted. All in all, it still is a very nice movie, acting was much better - for once Hermione was not shrieking so much that she was hoarse and ill tempered, and neither was Ron. Some of the humor in the movie was a welcome relief from past movies.