(CNN) "The Dark Tower" feels like a throwback -- a trim, competently executed "B" popcorn movie, adapted from Stephen King's books with ample action but also lots of clunky exposition. That's not a great prescription for a would-be summer blockbuster, but more an endorsement to watch when it hits cable.

Although King's name is an obvious selling point -- his spotty page-to-screen track record notwithstanding -- the film's underlying tone and template owe debts to another Steven, Spielberg. From its adolescent hero discovering his greater purpose to the drawings that channel images deeply embedded in his consciousness, themes present in "E.T." and "Close Encounters of the Third Kind" initially come to mind.

Of course, part of that has to do with the myriad sources that King drew upon in establishing this universe, which has been awkwardly condensed to fit into a 95-minute movie. The result is a film whose plot is sheer simplicity -- young boy teams with grizzled man-of-few-words to save the world -- while allowing the details to basically just spill out in between fight scenes.

Tom Taylor plays young Jake, whose disturbing visions have his widowed mom ("Vikings'" Katheryn Winnick) at her wits end. In fact, she's about to commit the lad to an asylum when Jake receives a tangible clue that his intricately sketched dreams are real, stumbling through a portal into Mid-World, an imperiled alternate universe that threatens our own. "What happens in one world echoes in others," Jake is told.

There, he meets Roland (Idris Elba), the last surviving gunslinger. A brooding knight, he has sworn vengeance against Walter (Matthew McConaughey), an evil sorcerer determined to bring down the Dark Tower, thus letting demons escape and wreak havoc on their domain.

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