I think they did a really good job with Narnia. I haven't seen Prince Caspian, but the Lion, the Witch and the Wardrobe was good. They were very faithful with the books and the battle scenes were awesome.
Plus, Animorphs is intended for children. It's a childrens series. So is Narnia and Harry Potter.
You're right, it's intended for children, I'm not denying that. However, there are fundamental differences here and I don't think that can be denied. Just because Animorphs should by nature disturb children, that doesn't mean it's unsuitable for them.
Narnia and Harry Potter never really pushed the envelope of what's acceptable. Yes, both discuss morality and good V.S. evil etc. But did you ever see either of those two older Narnia kids stab a guy in the throat with one of their swords and watch him bleed, having to deal with the aftermath of it when they got home and went to sleep?
Of course not, that would be completely inappropriate for this kind of movie. But in Animorphs? That kind of thing happened in virtually every single book, whether it be Rachel or Jake ripping Hork-Bajir up, or Marco TEARING A BIG WORM apart and spilling its guts onto the floor, the book even going as far as to describe the reeking smell.
You can use the "it's intended for children!" argument all you want, but name me one scene in either the Harry Potter or Narnia series that included ANYTHING even half that vile.
That's exactly what I'm getting at here: not only is the computer technology present in films like Narnia nowhere near sophisticated enough yet to make living breathing animals look believable and realistic, but an Animorphs movie should have so much more in common with a war movie than with Narnia anyway!
Of course Animorphs was a children's series. It was just a children's series that stood out from the pack, one that had the guts to tackle issues a little over the heads of the audience. It was educational in a sense, moreso in the realities of conflict than in the expected "good v.s. bad" manner. You can't compare it to children's series as a whole, because things happened in those books that were SUPPOSED to scare and shock the hell out of them. It might be intended for young readers, but you also need to realize it was also intended to make them think, and make them uncomfortable.
Those elements will never in a million years make it into any mainstream movie production, and yes, I can guarantee that. This is the point that is no longer opinion, and becomes practical.
You want an Animorphs movie? Better be ready to make some major plot compromises and throw away a good chunk of character development. People have neither the patience nor the stomach to see this on a screen, and any studio executive with any sense, or director with any conscience, is going to think the same.