It may be the height of condescension to shruggingly praise low-budget, Christian-themed family films for having their heart in the right place, but that’s about the best that can be said of Bill Muir’s middlingly earnest “The Lost Medallion: The Adventures of Billy Stone.” With its godly themes confined to an otherwise entirely superfluous framing device, this kiddie action-adventure works up just enough lukewarm swashbuckling energy to pass muster with bored young children and the Sunday school teachers entrusted with their care, which seems to be the extent of its ambition.

Shooting straight for goopy sentimentality right out of the gate, the film opens with a middle-aged man (Alex Kendrick) making a misty-eyed detour to a local foster home en route to a baseball game, where he’s pressured by assembled moppets to tell a story. He picks the two saddest cases in the room and plugs them into starring roles for his improvised tale: Billy (Billy Unger) is a crafty archeologist’s son living in a fictional South Pacific island, searching for a magical medallion whose origins are detailed in a strange interlude that’s half storyboard, half animation. Allie (Sammi Hanratty) is cast as his Lisa Simpson-ish, know-it-all sidekick. For reasons left weirdly unexplained, the evidently 11-year-old Billy owns a motorcycle.

After eventually tracking down the magic medallion, the two tykes are captured by a malicious developer (Mark Dacascos) with eyes on the trinket. Thanks to a magical quirk that this reviewer is still puzzling over, Billy and Allie escape by time-traveling 200 years into the past, where the natives hail Billy as a deity, a child royal (Jansen Panettiere) eyes him with suspicion, and a rival warlord (also Dacascos) plots an invasion.

It’s not until here, after a long procession of introductory prologues, introductions and reintroductions, that the film finally kicks into gear. But once it does, it allows Billy and Co. to race through jungles, jump off waterfalls, befriend an ancient Chinese stereotype (James Hong), and avoid the pursuit of two bumbling henchmen (one of whom, unaccountably, dresses like a Circuit City cashier while intoning threats like, “We sleep not ’til this mission be complete!”). The child actors all deliver their lines with steady enthusiasm and uneven verisimilitude, and “Iron Chef America” host Dacascos spends his screentime furrowing and unfurrowing his overactive brow with pitched aggression.

Technical specs and visual effects are extremely lo-fi, but the filmmakers make the best of what they have.

The Lost Medallion: The Adventures of Billy Stone

Reviewed at Wilshire screening room, Beverly Hills, Feb. 20, 2013. MPAA Rating: PG. Running time: 98 MIN.

A MeThinx Entertainment release and presentation of a Wooden Door production in association with Downes Brothers Prods. Produced by Bill Muir, Kevin Downes, Michael Scott, Bobbi Downes, Jamie Muir, Phillip Moses, Mark Burman, Wych Kaosayananda. Executive producer, John Duke.

Directed, written by Bill Muir. Camera (color, DV), Brian Baugh; editor, David de Vos; music, Marc Fantini, Steffan Fantini; production designer, Mona Nahm; costume designer, Chantika Kongsillawat; art directors, Sittichok Pungkarutanan, Rakpan Thanadpojanamart; sound, Chai Khongsirawat; visual effects supervisor, Jeff Goldman; casting, Beverly Holloway.

With: Billy Unger, Sammi Hanratty, Mark Dacascos, James Hong, Jansen Panettiere, Alex Kendrick, William Corkery, Hal Rudnick, Sidney S. Liufau.