In the undersea town of Bikini Bottom, SpongeBob (voiced by Kenny) is just too smiley and optimistic for words. He finally loses the plot when his cranky boss (Brown) fails to promote him to manager of the new Krusty Krab. But he gets a chance to prove himself travelling with his starfish buddy Patrick (Fagerbakke) to the dangerous Shell City to retrieve King Neptune's (Tambor) stolen crown and clear the boss' name. And don't forget the helpful princess (Johansson), the ruthless hitman (Baldwin) and the megalomaniac Plankton (Lawrence).

If there's a message here it's that old chestnut about valuing the kid inside you. SpongeBob and Patrick are uncontrollably juvenile, and they of course think they need to grow up in order to face the horrors of their epic quest. But the filmmakers refuse to get bogged down by this underlying message and instead focus on the warped and goofy humour that floods each frame.

Everything is wonderfully ridiculous, from the quirky and surprisingly well-defined characters to the textured animation and various live-action elements (a pirate framing story and a hilariously preposterous appearance by Hasselhoff). And there are fantastic touches such as Bob and Patrick getting "drunk" on ice cream, the king's oblivious vanity, the Bubble Party in the Thug Tug. It's just so deeply, utterly daft that you can't help but love it. And the characters are voiced with warmth and personality that balances the absurd designs perfectly.

It's the kind of film that children will love for the colourful craziness, while grown-ups revel in the astute spoofery and overall silliness. The story is just knowing enough in its satire and accurate enough in its themes to make it deeper than it looks. But the real point is to just have fun. And that's certainly enough.