A little uneven with a documentary style 1st half and full on action finale that seemed to drag and be put in the film solely to show off the alien weapons and blow people's heads off. When the film finds a balance it's at it's best-much like Children of Men-showing both brains and action.
Much of the charm and wit has left the series by this point. It's still fun and the climax with the train is exciting like in previous installments. However at this point it's all been there done that.
No other films quite have the heart and charm that Pixar provides over and over again. The beginning montage may be one of the most gut wrenching beautiful moments on film. (It reminds me of the montage in Toy Story 2).The film manages to be simple, clever, silly, thoughtful, intelligent and just plain fun! A film about an old man tying a bunch of balloons on his house should not be this entertaining and smart. But UP is up there with all of Pixar's other classics.