There's no reason to beat around the bush, Percy Jackson & The Olympians: The Lightning Thief only exists because Harry Potter is popular. That's not a slight on the literary series, as I've never read any of Rick Riordan's young-adult novels and we're here to talk about the movie, anyway. Regardless of the film's origins, it's clear from what ended up on screen that this came into being because movie theaters are a marketplace and, after the tepid reaction to Eragon, Twentieth Century Fox had no competing product to lure in the coveted Hogwarts demographic. So they scoured the bookshelves of their local Barnes & Noble and picked up the first popular, but more importantly, un-optioned fantasy series they could find.
It must be frustrating to work under those circumstances, to have to produce a product in the shadow of the colossus that is Potter. I imagine that Fox selected Christopher Columbus, who directed the first two Potter films, and essentially told him to do it again. And there's nothing inherently criminal about that. It's silly to dislike a movie just because you know its dreams were born in accounting and not creativity; and it's even sillier to spurn movie Y solely because movie X did it better. It is reasonable, though, to dislike a movie because it's just not good.
Percy Jackson starts off okay. We're introduced to the title teen right before he learns he's the son of Poseidon and that he has two weeks to return a lightning bolt he didn't actually steal, lest Zeus start a Godly war (somehow without using the most powerful weapon in the world that was just stolen from him). But this promising riff on what a hidden world with orphaned Demigods might be like soon devolves into a by-the-numbers fantasy 'adventure' that literally has to follow a map to its inevitable and obvious conclusion.
Craig Titley's script is a vacant, clinical autopsy of superior fantasy films that exerts no effort to deliver anything out of rhythm. Beat for predictable beat we follow Percy as he discovers that his world has been turned upside down and that his best friend (Brandon T. Jackson) and favorite teacher (Pierce Brosnan) are mythical creatures. However the problem isn't that we've all seen the 'boy has a destiny he never knew about' through lines before, it's that Percy Jackson is a boring hero joined on his quest by two boring friends. Despite the best efforts of the 17-year-old Logan Lerman, who does a commendable job of reacting with awe and wonder to the CGI beasts that tower over him at regular intervals, there's just no investment in his plight.
Even that might be acceptable if the fantasy at large were, well, fantastical, but it's not. Every single costume in the movie looks like it could have been acquired at a Renaissance Festival, while every computer-generated myth looks as though it would have been cutting edge back when Columbus unveiled the Sorcerer's Stone to the world. For a movie that's supposed to attract audiences with imagination, there's a remarkable lack of it on display throughout the production. And considering its run time is a minute shy of two hours, there is plenty of time to do the movie's job for it and fantasize that what's on screen is better than it really is.
Kids who, by the blessing of the movie Gods, don't know any better are sure to at least be distracted enough by digital hydras and lightning flashes, but the parents or older siblings who had to escort them to the theater for such a privilege will be wishing for sweet release from its lifeless grip; particularly when Percy and friends trip out on magical Lotus leaves while the camera whirls around them set to the tune of Lady Gaga's Poker Face. And no, I'm not kidding.
There are a few rogue moments of sporadic inspiration, however. Uma Thurman as the sultry Medussa hits like a refreshing elixir, adults will get a kick out of wondering why Steve Coogan is playing Hades, the God of the Underworld, and all the ancient mythology might even inspire some viewers to brush up on their Greek. Unfortunately even these distractions are not enough to make you forget that sometimes even corpses twitch with the appearance of life.