There is a long tradition of non-canonical works about Baum's fictional land, and people in all different areas of arts and media seem to love the idea of recreating the classic any way they can. It only seems natural that Marvel would give it a shot, and Shanower must have seemed like their best candidate in choosing a writer. His history with Oz not only includes the five Dark Horse graphic novels but his illustrations for another set of Oz comics as well. Unfortunately, a history with Oz doesn't necessarily produce an adeptness at retelling a great story.
Shanower's writing is rushed, to say the least. Of course, he is trying to fit a novel into an 8-issue comic series, but that's no reason for the speed through which he blows through the story, much the way his tornado already begins to blow through by the third of 32 pages in the first issue. Maybe the assumption is that readers won't mind, as they know the story so well, but when Dorothy expresses her desire to return home from Oz I have no clue what she is yearning to return to. The story really lacks a sense of who Dorothy is and where she comes from, despite the images we are shown of her Kansas home. Henry and Em are merely a "farmer" and a "farmer's wife," and we have no idea what their relationship to their niece is. It proves that you can't rely on the classic status of a story to carry the weight of it adaptation.
The saving grace in all this is the artwork drawn by Skottie Young. Much different from the style typically adopted by Young in his artwork for other Marvel comics, the images seem like a combination of artwork in a typical children's book and standard comic book art style. The outlines are bold but also rough and sketch-like. The characters each have their own visual quirks, bringing life to them in a way that Shanower has not. From the artwork alone you can see Dorothy's innocence and naivete, and even the artwork depicting the hideous evil witches shows a lightheartedness suitable for the children's story.
Aside from individual characters, the backgrounds and scenery created by Young and the colorist Jean-Francois Beaulieu are impressive. Images of Oz and Munchkin towns are vivid and exciting. Even the drab colors of the simple Kansas landscape were beautiful.
Overall, it isn't a bad choice for some of the younger comic readers and even some older art-oriented readers. Just don't expect to be wowed by an imaginative retelling of the well-known story.