As mentioned above, Norse Mythology is a collection of stories, a re-telling of myths collected from multiple sources and presented in Neil Gaiman's signature style. Other readers might disagree, but I notice C.S. Lewis' and G.K. Chesterton's influence when I read (or in this case listen to) Gaiman. He writes with a clean crispness, wasting no words, in a way easily accessible for younger readers but also engaging enough for an older audience. This style suits these stories perfectly.
As each story unfolds and the reader is introduced to the gods, goddesses, monsters, and men, a meta-narrative begins to unfold. There is a sense of forward momentum despite inconsistencies in the stories and no discernible timeline. The story unfolds from creation to Ragnarok and beyond, and it is these "event story" landmarks that provide a sense of a beginning, middle, and end.
Despite having read most of these stories before, I found myself enthralled, even learning new details of my favorite Norse myth (Thor and Loki in the land of giants). It is a story I've told my sons dozens of times at bedtime, and now I have a new way to tell it. For this reader, I think that makes this book a overwhelming success. It has achieved the author's stated intent. Listening to Gaiman tell his own stories was also extremely satisfying. He's a shockingly great narrator, providing great variety with his character voices and providing his intended pace.
If you enjoy tales about gods and mortals, colorful explanations for the world's natural wonders, and learning about the stories that have helped shape our culture, this book is for you. It's a relatively short read (or listen) too, clocking in at 12 hours on audiobook (or 6 if you listen on double speed like me). If you're looking for something a little different to break up your reading or just for something you can read incrementally without forgetting a bunch, I recommend you pick this up and share it with your family. You won't regret it.