it is hardly like the book at all for one to get to hell they must bride the guard who wear suits and is very materialistic, the entrance to hell is also a lobby where they take an elevator then a boat. but in the film the entrance is in the holly wood hills and the boats man is dressed in a ragged robe and not a fancy suit like in the book. I understand needing to move things along in a film, but even still, it would be better if it were more accurate to the book.
Not to mention he doesn't know his father is poisden until capture the flag where posiden claims him, then he moves into his own dorm. Annabeth is also not book accurate she has (in the book)blonde hair and grey eyes however in this film she look scarily like percy what with being a brunette and having blue eyes.
I do believe that if this film could be done again i think it should be done with the book as a guide almost script. i think it would be far more enjoyable that way.