I'll start off with what was great about this movie. Technically, it was all-around stunning. Great use of imagery, camerawork, direction, editing, and special effects. Kudos to the director (and his mother, also).
Scriptwise, this movie was the first real adaptation, as opposed to, "Let's take the book and put it exactly up on the screen." They changed some things around, combined some scenes, deleted the unimportant, and I think it worked.
ONLY ONE QUIDDITCH MATCH THANK GOD.
Where they tripped up? Storywise, they left out some rather important things. Since this strayed from the book some, it also seemed to assume you had read the book, and could fill in any blanks. I'd have to take my mother to be sure, but I'd guess those who hadn't read the books wouldn't understand why the rat turned into a man, and who he was exactly. Or why Lupin knew how to work the map.
Dear Fangirls: No, I don't see the Remus/Sirius love. Never have. If you want to wander into Marauderslashland with me, I'd believe James/Sirius more, honestly. Also, what was up with Remus' reverie about Lily? "Your mother was there for me at a time when no one else was. She was a wonderful woman..." OMG Remus x Lily OTP.
>^..^