Not all of want our kids growing up on the candy floss that is Disney, or with their heads in the Puritanical sands. That being said, this is a pretty mindless movie and really just good for idle background noise.
Is this a movie for incredibly young children? No, aim more for 11+ with this one, in terms of content. As far as intellectual level goes, even small children would get bored.
The animation style is somewhere between Tim Burton, Jimmy Neutron, and Double Fine's video game "Psychonauts". There are some nods to Mr. Burton throughout the film, which is nice, just as it's nice to see more than one person putting out movies geared for the more Goth among us.
But, and I can not stress this enough, don't expect mental stimulation from this feel-good gothy film. Expect some pretty color combinations, darker themes, and a lot of useless dialog.