Some sort of character development has occurred between original and sequel: teens Vega and brother Daryl Sabara are looking for greater independence from their parents (Antonio Banderas and Carla Gugino), who've been showing signs of becoming civil service office drones, until the mission comes along that will throw them all back together. The pre-credits sequence has Bill Paxton as the owner of a theme park from which the president's daughter needs rescuing by not one but two sets of spy kids (including Emily Osment, sister of Haley Joel - and the family resemblance in looks, if not quite acting style, is really quite something).
When the characters arrive at the island of the title - and it takes Rodriguez an awful long while to get them all there - it's a disinhabited Azteca affair populated by rogue scientist Steve Buscemi and his Harryhausen-inspired menagerie of genetically modified zoo creatures; and it's a second theme park, one in which the connecting tracks of narrative are less important than endless, often nonsensical spectacle. (The sudden lurches in plot logic, with the kids zipping about from one point on the island to another without so much as a throwaway explanation, get wearying after a while.)
The central premise - that these kids have been recruited to do the work of adults - still delivers a fair amount of fun: the teenagers sulk on learning that key assignments have been handed to their rivals, and - upon being suspended from active service - the youthful Sabara looks forward, with an old man's sigh, to "catching up on all those dreams and plans I had to put to one side". And there's still something of a cleverness in what little plotting there is here: on arriving at the island, the kids find the gadgets they've previously been comparing like brand-new sneakers in the schoolyard no longer work, forcing them to use whatever's in their heads that hasn't been rotted away by text messaging, Limp Bizkit records and Sunny Delight.
One of the pleasures of the first film lay in its casting of unexpected faces in stock kid-pic roles. The follow-up more or less wastes Cheech Marin, Danny Trejo, Alan Cumming and Tony Shalhoub in one- or two-scene reprisals of their roles from the original, and it's a sign of how low the sequel's ambitions are that where the first film delighted child-accompanying mums everywhere by casting Banderas alongside George Clooney as the head of the surveillance operation, Spy Kids 2 has to make do with Christopher McDonald as the President of the United States. New additions include Holland Taylor and Ricardo Montalban in the cursory roles of Gugino's parents, and Buscemi does what he can in a rushed-through sad professor skit, but the lack of an identifiable villain counts against any excitement or tension this sequel might generate. Mostly unobjectionable, and you're bound to know at least one eight-year-old who'll place it alongside the original in their list of the greatest films ever made, but this material plays just that little bit flatter second time around.