Two kids (Dunst and Bradley), bored on a wet afternoon, discover an ancient board game and being to play. By magic, the game unleashes jugle beasts and flora into their New England home, along with a man who has been trapped inside the game for a quarter of a century (Williams).
Though entertaining, Jumanji - adapted from an idiosyncratic children's book by Chris Van Allsburg - feels more like a package than a movie: Jurassic Park-style CGI effects, Gremlins-style childhood traumas, Honey I Shrunk the Kids-style Joe Johnston direction and Robin Williams-style Robin Williams. On a scene by scene basis, it is mostly great fun but suffers from a contrived script which repetitively drags characters back to the eponymous magical board game for another effect-producing throw of the dice.
The story opens in 1869 with some kids burying the magical game Jumanji but without explaining who made it or what it's for, as if that stuff were being left for the sequel, then flashes to 1969 where the thing is rediscovered by mixed-up rich kid Alan (Adam Hann-Byrd) and a few turns unleash African bats into New Hampshire and send Alan off to jungle hell. A quarter of a century later, the film finally starts proper as orphans Kirsten Dunst and Bradley Pierce restart the game and unleash the grown up Alan (Williams) along with a collection of flora and fauna that run riot through the town, causing chaos.
The CGI creeping vines, capering monkeys, attacking alligators, fluttering bats, hungry lions and stampeding hordes are genuinely amazing: as hyper-real and odd looking as Van Allsburg's original illustrations. For once, the strange look of CGI is turned to its advantage as the jungle animals are supposed to be fantastical. A major trick is missed, however, by having the sole human to emerge from Jumanji to be a regular actor rather than an effect. This undermines the weirdness and allows Jonathan Hyde - who does a Captain Hook-like double as Alan's tyrannical father and a gun-toting white hunter - to overact shamelessly through too many slapstick stunts.
There is quite a lot going on in the film, which disguises the thinness of the central idea (African chaos erupts from board game at every turn). Williams' Tarzan act is a reprise of his Peter Pan and the less-than-stellar supporting cast - with the exception of the excellent Hann-Byrd and an amusing Bonnie Hunt as Williams' neurotic old girlfriend - just gape in amazement or consternation as the effects boys run rampant.
It's rampant fun while you're sitting through it - especially if you're under 13 - but there's really not that much to keep you sucked in beyond the credits; a half-term crowd-pleaser you'll have forgotten by summer.