The seriousness of some of the issues here can surprise you--life and death survival, questions of loyalty, sacrifice and courage, and just as they start to weigh down one's enjoyment, comes madcap, skillfully done comedy to wash the heavy stuff down.
The animation is excellent, willfully artistic and stylized, but rather serious in the way it depicts backgrounds and characters. The writers demonstrate a certain gleeful unpredictablity in the plot and jokes, but the audience enjoys being gulled and deceived, and all ages seemed to appreciate it in the crowded theater in which I saw it.
Oh, and give an acorn to a frantic rodent, would you?
Four out of five stars.