My problems with it are the same as with most screen adaptations of young adult novels...they spend so much time struggling to explain the world they're creating that they forget which parts of the story people want to see...they figure that people (kids)
The Lightning Thief is all crass ineptitude and lost potential. Columbus' infantilizing of any character depth and use of leftover Harry Potter special effects will amuse only the smallest in your pantheon.
Another attempted launch of a teen-aimed franchise, but this show-boat is rowing through the motions. Seen-that, been-there fantasy-epic stuff with dialogue more wooden and hollow than the Trojan Horse.