So, for a children's book, this is bad. The text is quite long and rambling, and wouldn't keep the attention if you were to read the story to a child. Now, it MIGHT work for older, experienced readers, but it's too complex for early readers, so it being a picture book doesn't fit well, either. Really, the only people I see needing this are those who love the ballet it's based upon, and they're going to buy things no matter the reviews.
The artwork is also pretty bland for a children's book. The shapes are very vague and blurry, with no real emotion. That may be the artist's style, and perhaps fit for a gallery showing, but, in a children's book, again, it does not fit. There's nothing to keep the attention of young readers. So many images are just close-ups of faces or long shots of scenery, lending nothing much to the tale.
If it's in your library and you pick it up, try it. But I'm not sending anyone out to give it a shot, and I certainly don't recommend a purchase unless you know it will be loved.