Mike Newell director of Harry Potter and the Goblet of Fire describes the film as "a bit different" and attributes this because he is the first British director of the series.
Newell on Goblet of Fire being different from the previous movies:
This one is bound to be a bit different, because I'm English and the others weren't. Whether anyone will notice, I don't know, but I hope it has a kind of authenticity. And it's a little darker than the others, because these kids are growing up, and they have to face stuff that they haven't had to before. But the real thing about it is that it's a terrific adventure story and a really good thriller.
He also comments that the most frightening aspect:
Jo Rowling is very, very interested in what happens to these people when they hit puberty. So you've got to take it on, and of course it's painful, as we all remember it. But it's also terribly funny.