There was a time in the not-so-distant past when kid-friendly adventure films abounded — and they were good. The early 1980s gave us “E.T.,” “The Goonies” and “Labyrinth,” to name a sampling that delighted little ones and their larger companions.

Not to get wistful, but “The Lost Medallion” brings to mind that time, even as it fails to live up to those films. It certainly suffices as squeaky-clean entertainment with a well-intentioned message about self-worth, but it’s overly sentimental, and a late-in-the-game religious message plays like a bait-and-switch.

The movie begins in a foster home where a visitor is unexpectedly tasked with taking over storytime. Luckily he has impressive improv skills. His convoluted adventure follows Billy Stone (Billy Unger) and his brainy, orphaned best friend Allie (Sammi Hanratty). The pair of kids are on the hunt for an ancient, magical pendant, buried somewhere in the idyllic island they call home. They aren’t alone in this search. Billy’s archeologist father and an evil man, who appears to own much of the town, also are on the hunt.

But the medallion turns out to be more than Billy and Allie bargained for; while wearing the pendant, an ill-timed phrase lands them back in time 200 years. When the villagers see the kids from the future — toting the hamlet’s lost medallion, no less — they see salvation and protection from a homicidal warlord named Cobra (Mark Dacascos). He, in turn, sees eternal life and rule. And if he gets his hands on the medallion, Billy and Allie will have no way of returning home.

The story meanders a bit, but there is action and suspense, plus some comic relief in the form of a Mr. Miyagi type named Faleaka (James Hong).

But one stock character can’t compensate for the rest.

(At the Barrywoods.)