Game vs. Movie
So I played through the game before I got to see the movie. Because the game is based on the movie, I had certain expectations about the movie and felt a bit let down because I think the game excelled above the movie in instances.
McGonnagol vs Snape
Game - MocGonnagol declares "You are a coward severus, and you always have been". fight starts
Movie - no dialogue. fight starts.
McGonnagol Troll Fight
Game - McGonnagol valiantly declares she will defend hogwarts. Awesome fight scene where you defeat giant troll.
Movie - McGonnagol does something I guess.
I was really excited to see McGonnagol kick some ass in the movie because the game portrayed her in that way. I was sad when there was no scene of her directly taking on a troll.
Game - sadly, he is not a useable character nor does he shoot his death star laser spell down the bridge
Movie - Dumbledor casts his awesome death star spell. very brief, but cool.