Ultimately too silly and pointless. Yes there is the gilded cage metaphor but probably most kids would miss that. Forgettable. Instantly.

Animation is, as we have come to expect, super-real. The plot-line could best be described as thin but tenacious. Although the ending seemed arbitrary to me.

The sewer underworld is a suitably disgusting reflection of the world above and, somehow, wealth and money seem to count for a lot there too. Oh yes, and there's a romantic interest with the female being the smarter, more savvy and go-getting of the pair - this in itself is rapidly becoming a tiresome (anti) stereotype. Probably your kids will love it though.