Children Who Chase Voices is an undisguised love letter to studio Ghibli and the anime of the early nineties. With a setting and visual elements reminiscent of Nausicaa of the Valley of the Wind and character and monster design that you could insert into Princess Mononoke and not notice an intrusion, and a narrative structure and a plot following conventions from fantasy anime from that era (championed by Escaflowne, which the movie references visually at least a couple times,) it is clear for the long-time anime watcher that Makoto Shinkai is crafting a beautiful "thank you" card to the medium that inspired him to become who he is now.
It is also -as we all have learned to love and expect- breathtakingly beautiful in its large panoramic vistas of long-grassed fields and cloud-layered, color-tinted skies and his signature railway crossroads. The world is imaginative and vibrant and the action scenes beautifully animated and choreographed. Speaking of expectations, the theme of "distance" is heavily played but manages to never cloy.
However, the movie falls prey to its own good intentions. Trying to include too many trappings and conventions of the medium he's paying an homage to, the result is not unlike that of a patchwork that had to sacrifice character development and proper, cohesive narrative to make room for all of it. The jerkiness in plot and character development make the story hard to believe and the characters hard to empathize with, giving the general effect of having cut most of the "boring" character-establishment, emotion-development, sense of wonder and personal reflection to give you all the thrilling plot-advancing bits it could pack in two hours.
Without a doubt, this story would have been much better served as a 24-episode series than as a movie and that without adding much new, really: Just filling the blatant holes in the narrative and pacing the events properly. Having said that, I understand why this is a movie and not a series: its very own premise makes it wholly unoriginal and derivative which would make the series painfully unnecessary and redundant. As a (superbly visually beautiful) movie it stands as a statement of love and gratitude rather than as a rehash or a cash-in.
At this point, I think it's necessary to acknowledge Makoto Shinkai's shortcomings as a teller of epic narratives, which we have seen in his other plot-driven movies. Hopefully, he'll become aware that his real kind of genius is that of the deeply personal, character-driven stories and manage to expertly make of that the focus of the big, sweeping epics he obviously loves to tell.
I still wholeheartedly recommend this movie, specially if you are a fan of nineties anime and studio Ghibli. Its plot may leave you slightly unsatisfied but everything else will make you smile.