Pros: Hogwarts is fantastic; licenced music; voiced by some of the cast; cool analog stick spell casting
Cons: Dull quests; excessive treking; limited shortcuts; weak story integration
The opening 10 minutes of HP OotP contains all the good and bad things in the game. Your introduction to Hogwarts is breathtaking and the analog stick spell casting makes immediate sense. However, unless you've seen the film or read the book, the cut scenes do not tell the story successfully. Worse, the tasks and quests have little to do with the novel's plot.
The game design is clearly inspired by Bully, but toned down in scope and difficulty. Exploring Hogwarts is initially enjoyable, and finding all its secrets proves to be fun. However, many tasks resort to you treking from one side of the school to the other for nothing more than greeting a new character. Shortcuts are provided but they are of limited use and never really reduce the time taken to traipse across Hogwarts for the 100th time.
The game clearly has great potential and the core elements are there. If EA can integrate the story into the game and reduce the pointless school treking, the next installment could be a real winner.