Like many book to movie translations the Christopher Columbus/ Thor Freudenthal directed Percy Jackson and the Olympians films were major box office flops. To see a decent adaptation of the plot of even one of these books you would need a longer time slot than 90 to 120 minutes ( average movie length ). Especially if you want to dive deeper into the characters and their back stories along with each and every one of these key plot details...
Percy's relationship with Sally
Percy's school/social troubles
The bond between Annabeth and Grover
Explore Camp Half-Blood a little better
The whole conflict between Percy and Ares
And also Kronos like that was way off.
I'm not saying the movie was bad.... Actually that's exactly what I am saying it was terrible plus we missed the entire ride in the back of the truck with the zoo animals and in all fairness that's one of the most important parts in the entire series. I firmly believe that a TV series would be the best on screen depiction of the Percy Jackson series and maybe if things turn out well HBO would do and make just as amazing as the have made Game of Thrones but with less NSFW scenes cause this is a story about teenagers.