I read and greatly enjoyed the first 3 Earthsea books when they were new; when 20 years later, another book came out, what I read about it did not incline me to read it -- it seemed to be more a repudiation of what went before, rather than an extension.
So it was with a little trepidation that I went to see this movie. And alas…
Happy Ghibli fantasy land folk trotting around, just like we saw them in Nausicaä or Laputa. White people. Oops! One big systematic failure there -- the folk of the Archipelago are dark of skin (that was part of the point, to be antithetical to the blond barbarian hero stereotype). Names grabbed from various books, of people who never actually met, entirely, I am sure, to provide a hook for the typical Ghibli-girl. Themes from the start of book three segueing into what I am told was the end of book four, with a stock Ghibli subordinate-villain prancing around to try and hide the join. And the typical bit of environmentalism building on the notion of balance; a sad confusion of the interior and the exterior (the same confusion that leads some young men to blow themselves up on public transport).
There are other bits I could go on about, but those tend to be inherited from the source material. As it is, the film verges close to Ghibli self-parody under the direction the younger Miyazaki (at least they refrained from flying machines).
Probably best suited to young teens who haven't read any of the books yet.