I watched it yesterday morning, and unfortunately, my 5 year old is a scaredy pants... She spend most of the movie sitting on my lap looking away. Not sure what ticked her off, because even the growing of the castle was something she was scared of. I may need to be aware of this for other movies and books in the future. I doubt I can start with the Hobbit any time soon.
My 3 year old loved it, until he saw my daughter cower and thought that it looks much cozier hiding on my wives lap than sitting in his own seat.
And what's weird (or really, not weird at all if you're any way familiar with kids): they couldn't sop talking about how great the movie was afterwards. Maybe they just don't really know how to deal with excitement, and project fear instead?