Unlike the Prisoner of Azkaban (the best Harry Potter movie ever!), this movie lacked any real suspense, drama or action. I almost fell asleep during this movie waiting for something to happen.
I also don't understand why Dumbledore allowed himself to get killed. If he was such a great wizard (as he obviously was), he would not have allowed a mere student to disarm him. But perhaps this will be explained in more detail in the upcoming movies.
The movie definitiely had its light-hearted and funny moments.