“Percy Jackson and the Olympians: The Lightning Thief” isn’t very subtle regarding its intentions: it wants to be the next teen-lit sensation to make good on the big-screen. Based on a series of bestselling kid-novels about Greek mythology, “The Lightning Thief” is clearly a calculated film that aims squarely for the “Harry Potter” demographic.

While there are many similarities to be found between this would-be film franchise and Hollywood’s “Harry Potter” behemoth (“Lightning’s” plot is essentially “Potter” gone Greek), there is also a glaring distinction separating the two: the “Potter” films are generally enjoyable, while “The Lightning Thief” is somewhat less than mythical.

The film opens with young Percy (Logan Lerman) just trying to survive high school. He suffers from dyslexia (though he can decipher ancient Greek quite well) and only feels at peace while meditating at the bottom of the school’s swimming pool (for seven minute intervals).

After a field trip to the museum’s ancient Greece exhibit, Percy learns some surprising news: he’s a demigod, the offspring of a human mother and a mythological god. In Percy’s case, it’s Poseidon (Kevin McKidd), the Greek god of the sea (amply explaining Percy’s fondness for water).

But there’s no time for Percy to let this revelation sink in. He’s in trouble, as someone has stolen Zeus’ lightning bolt, and an angry king of the gods has decided to blame our hero.

Soon Percy is whisked off to demigodding school, accompanied by old pal and secret satyr Grover (Brandon T. Jackson), who has managed to keep his goat legs hidden in a pair of Levis. But Grover’s feat is surely outdone by Percy’s high school teacher, Mr. Brunner (Pierce Brosnan), a centaur who has escaped notice by gliding around in a blanketed wheelchair.

This sort of goofy logic is about the only charm “The Lightning Thief” has to offer, but it can occasionally be entertaining.

It’s campy fun watching the movie update Greek mythology to fit the 21st century. The gods have moved from Mt. Olympus to the top of the Empire State Building, and the gates of Hades now rest behind the iconic Hollywood sign. It’s whimsically anachronistic to see Medusa (Uma Thurman) toy with an iPhone.

But these amusing sight-gags are probably the most original moments to be found in “The Lightning Thief.” This is a film that feels like it’s been made before, but under the “Potter” banner. It plays like a shameless attempt to distill the essential story components necessary for “Potter”-like success and infuse them with hip-teen sentiment.

The result is remarkably uninspired, as the “Lightning Thief” has all the superficial plot-indicators, but none of the underlying imagination. The movie’s CGI-fueled set pieces appear less than polished, and its script tries to circumvent genuine creativity with lame jokes and feigned attempts at relevancy (the current recession is a frequent — and tiresome — source for humor).

Director Chris Columbus, who helmed the first two “Harry Potter” films, tries to recapture that franchise’s casting success with “The Lightning Thief,” balancing the inexperienced lead-actors with veteran performers in the supporting roles.

But in “The Lightning Thief,” the strategy doesn’t pay off, as the film’s many stars — Catherine Keener, Rosario Dawson, Pierce Brosnan, Steve Coogan — feel misused, appearing in roles that amount to little more than cameos.

All these problems make “The Lightning Thief” feel a bit like a certain wooden horse from Greek mythology. This movie might seem like an inviting cinematic offering at first — but there’s hardly anything enjoyable to come out of it.

Rating: 2 out of four

Bottom Line: “The Lightning Thief” lacks ambition, tracing a “Potter”-esque plot while failing to assert any unique qualities of its own.