This is a fabulous book. It seems to be marketed as Magical Realism, but I think it slips over the boundary into Fantasy, and if that borderland is a place you like to hang out in, as I do, then this is perfect.
The heart of the tale is about belonging and about being an outsider, and how you can sometimes be both at once.
It's got a beautifully drawn relationship between two brothers, one who gave up all his dreams to care for the other when their feckless mother took off for a new boyfriend in Oregon, and the other who can't seem to quite fit in with anyone at all, including the big brother he idolises.
There's a scary villain (who maybe isn't evil, although certainly bad) and a beautiful maiden (who isn't entirely a passive damsel in distress waiting to be saved), and beasts and a horse who is a literal night mare, but not a nightmare.
The writing is lyrical, but not dense, in fact it's eminently readable. Although it took me 2 months to get around to writing the review about it, it's easy as pie to write because the book has stuck with me, and in fact writing this has made me want to go read it again. And I read it in a day the first time!
No book is perfect, and there are flaws. They don't matter. For instance, one of the characters is from Poland, and the Poland of the book may have been the Poland of the 1940's, but almost hilariously isn't the modern technologically up to date country of modern times. It jars, a little... but then it doesn't matter, because it's entirely beside the point and the plot.
I don't read YA as a rule, but I'm very very glad I read this one.