Summary It is no secret that the Percy Jackson movie adaptations got a lot wrong about the source material. Everyone, including Rick Riordan himself, has criticized the movies for their complete failure to understand the books and their most vital components. The Percy Jackson movie franchise only made it through two movies before buckling under the weight of its mistakes; the second movie awkwardly tries to correct some of the things from the first, to little avail.
Additionally, changing the characters' ages dramatically altered the movie's tone, hurting its ability to get through to the people for whom the story was written. The Percy Jackson books are a careful blend of lighthearted comedy and true danger, written for an audience around the same age as Percy, so they can see themselves in him and his friends. When Percy was reintroduced as a 16-year-old, much of the existing fanbase would have felt like the story was no longer for them.
The setting might be a lot kinder to these teenagers, but that's not really the point of the story. Clarisse is given a quest in the second movie, but this doesn't fix the plot holes created by changing the quest in The Lightning Thief. Percy — and Annabeth and Grover for supporting him — comes across as dangerously naive for basing his whole plan around simply explaining to Hades that he didn't steal the Master Bolt.
This also segues into Percy realizing that he will be healed by fresh water and that he can breathe underwater. In the movie, Percy realizes the former during training at camp, while some of Percy's other more specific powers are cut. In contrast, Percy's battle with the Hydra is too similar to many other fantasy action sequences, with a lot of fire and destruction before the heroes inevitably triumph.
3 The Percy Jackson Movies Cut Everything Cool From Sea Of Monsters Blackjack, Circe, and Blackbeard do not appear in the Sea of Monsters movie. Close The Lightning Thief cut one exciting aspect of the quest for the Master Bolt, but Sea of Monsters cut everything fun about the quest for the Golden Fleece.