If you were hoping for a witty and live action rendition of your favorite book as a kid, look somewhere else; this ain't it.
I REALLY tried to give the movie a chance but yet again, Disney did no justice to a fabulous book when recreating it for the screen. (Looking at you Percy Jackson.)
First of all the movie spent way too much time explaining the world. (Here I was thinking that only books had that problem.) The thing is, the book didn't have that issue. Books have to walk a fine line between over explaining and under explaining the world, and while many authors struggle with that, Eoin Colfer waltzed that line unlike any other. The movie spent precious screen time explaining scientific and magical aspects to the characters who should already be familiar with it, distracting from the movie. Movies don't need to explain how everything works, we watch them to see how it works.
Secondly, both Holly's and Artemis's utter brilliance were undermined by the movie. Artemis is a brilliant and manipulative child too smart for his own good, so why is Butler needing to explain anything to him?! Holly is an officer of questionable renown for sure but it was never questioned in the book that she was enthusiastic and (relatively) capable. (In the book we learn that she made some well-meaning poor decisions that hadn't turned out well while in the line of duty.) She's not some newbie officer who's never been to the surface and has no idea how things work!
The movie seemed like it couldn't decide who the the focus of the movie was and kept trying to switch directions every time the camera angle switched. Because of this and their over explaining of things, they left no time for good character development. They tried to get ahead of themselves in the story whilst also cutting necessary corners in the story. Like if Harry Potter had found out that the Malfoys are all death eaters in the Philosopher's Stone, or Katniss Everdeen learning of the existence of District 13 in the first Hunger Games movie. Yes it's part of the story but the characters need to experience some things together before we get there.
I had started writing this review when I was seventeen minutes in at a 1 star. I am now only changing my rating to a 2 stars because 1. the music was decent and 2. I think it was actually cast pretty well, but with an absolutely abysmal script and a subpar director there is not much an actor can do.