it's a real treat to watch visually. in one sense it appeals to kids because of it's fantasy world, and simply plot line of saving her parents.
but in another perspective, in case you were thinking it was really weird, it makes more sense when you think of the story as a metaphor for japan's modern economy. like that it takes place at a rundown carnival, failure of past glory. the japanese servents flock to whoever throws them the most gold, only to later see it melt away. the boy in dragon form is attacked by paper, representing blank checks. in this process of growing their economy, all the workers/japn lose their identity (have their names taken away by grandma). grandma is modern woman, working as mean boss, but kind and push-over for own child. the no-face/stinker is a polluted river god, commenting on wasting of environemnt and the false riches we gather from destroying it. her parents were turned into pigs because of their blind mass consumption.
there's also a lot of stuff that makes sense when you know japanese tradition and folk lore. but i don't know any of that stuff. someone explained things to me long time ago, but i forgot. maybe someone here can elaborate. like why she had to hold her breath when crossing the bridge?
but regardless of all that fluff, i just liked *watching* it and wish i had seen it on big screen. it started to feel magical early on when the carnival was changing at night and the boy turned around and started blowing dust out of his hand to hold them off.
(oh and there's also an interpretation you can make of the movie being a metaphor for modern prostitution in japan. there's some specific references with names and such that i forgot)