Oh well what can i say... the movie is a bit off context against the books. I think it'll better off to be a stand-alone movie and not based on the book itself because the plot is vastly changed.
I can understand the possible reasons of the director why he changed the movie plot because it's really hard to contain all the details of the book in more or less than 2hrs of movie. For all of you who have read the novel you're in for a surprise on this movie.
Let me enumerate to you guys some of the important parts of the movie that was either changed or removed:
1. No Clarisse and Ares. For those of you who have read the novel, you know the importance of these characters.
2. Hades was brought out bad guy and an antagonist when he was supposed to be a cool business-minded god.
3. Dropping the storyline of Hades' invisibility helmet and only making him want the lightning bolt.
4. Annabeth was the leader of the red team in the capture the flag not Clarisse, who was not included in the movie, thus making Annabeth the opponent of Percy.
5. Luke is like so evil and wise that he managed to fool the gods. Keep in mind he is only a demi-god.
6. No prophecy, thus making it the quest for the 3 pearls. If I can remember it right these pearls are only given to Percy by a naiad.
A good movie in terms of effects and only if you haven't read the books yet. But I won't suggest you to watch it unless you really wanted to.
