Walt Disney and Walden Media are marketing Bridge to Terabithia, their jointly-produced adaptation of Katherine Patterson's lauded children's novel, as a full-blown, effects-laden adventure. That's not what they deliver. At most, twenty percent of the film takes place in the fantasy realm so prominent in trailers, posters and other promotional materials.

Along with the quantitative dearth, the visual effects are underwhelming and prevent a magical cinematic experience. Moviegoers accustomed to the Harry Potter films and The Chronicles of Narnia -- also produced by Walden Media -- or any number of recent blockbusters aimed at families, will be disappointed by the mundane nature of the fantasy side of things. The movie was shot in New Zealand and the effects were designed by the same outfit that helped make The Lord of the Rings and King Kong memorable. You'd never know it.

Still, there is something worthwhile to counterbalance the disappointing visuals. The movie gains traction as an intimate, tear-jerking drama about loss and friendship, which suggests it's intended to appeal to adult caregivers and tween girls. Indeed, Jess Aarons, the eleven-year-old male protagonist, isn't a compelling role model for young boys. The message about overcoming pre-teen tribulations and conquering fears by exercising one's imagination translates into routine action.

Mind you, the strong female characters and the positive image of women conveyed are refreshing. Yet the film is caught somewhere between a boy's own adventure and a coming-of-age fairytale with requisite sexual undertones. The result is not so much a throwback to Disney features of the sixties and seventies but to After-School television specials of the seventies and early eighties.

Encountered in book form, when the awkward name Terabithia doesn't have to be spoken out loud, it's clear how the message of using one's imagination to vanquish adolescent tribulations would appeal to youngsters. The screen execution overseen by Gabor Csupo, the animator who created the clever Rugrats  cartoon series, seems forced, and the sentiment at the heart of the novel is conveyed in blunt fashion, relying on an abrupt plot turn.

Readers must exercise their own creative powers to conjure the forest realm into which Jess (the indifferent Josh Hutcherson) and his new best friend Leslie escape to elude any unpleasantness in their rural community. Jess is bullied and badgered at school and at the breakfast table where his squabbling sisters gang up on him. Enter the sprightly tomboy Leslie (AnnaSophia Robb), who teaches him to unchain himself and find refuge in an enchanted reality of their own devising. Until an unexpected tragedy ends their game of make-believe, this world is entered by crossing a creek on a rope swing.

Leslie instills the value of serendipity and free-thinking (her parents are both writers), encouraging Jess to pursue his talent for drawing. Meanwhile he has a crush on his music teacher (Zooey Deschanel), who also encourages him to keep an open mind and cultivate his artistic instincts. Along with the scene-stealing Bailey Madison in the role of Jess's youngest sister, Robb and Deschanel charmingly represent the spirit of Bridge to Terabithia. Jess is merely the passive recipient of their wisdom.

Depicting the world from a kid's perspective often entails making everyday reality seem extremely dull and a fantasy world super alluring. But because neither sphere is visually inspiring, Bridge to Terabithia can be interpreted as an unwitting spur to using one's own imagination. Many children in the audience will be thinking to themselves, "I can dream bigger and better than that!" 

(Released by Walt Disney Pictures and rated "PG" for thematic elements including bullying, some peril and mild language.)