To be honest, I just started listening to this. Me and Adam were watching the Blu-ray yesterday when I remembered how awesome the soundtrack was. The Bruno Coulais score is particularly moody. It might be a bit melancholy at times but this counteracted by a feeling of youthful optimism and exploration.

There is a They Might Be Giants track which is my least favorite, but it's still fun. My favorite songs are the ones with the Hungarian choir, like the tracks exploration and party. They're all gibberish with hints of French and Latin. I'm pretty sure this will be on my player all this week and perhaps the next.
Here's a sample of the one of my favorite songs: