Years ago, back when Neil Gaiman was still writing Sandman, I can recall reading a magazine interview in which he was asked if there was in any superhero character at DC or Marvel he would like to write. He replied that he felt he had a great Thor story to tell but that Marvel would never give him the creative freedom he would need to tell it. When I saw that Gaiman had written a book called Norse Mythology with a big hammer on the cover, my first thought was that he had finally written his Thor story.
Instead what we have is a straight ahead retelling of some of the key Norse myths. Sort of an Edith Hamilton's Mythology for the Norse gods. This is clearly a topic that Gaiman is passionate about, and his description of Ragnarok is the highlight of the book, but these are stories that have been told many times. In his introduction, Gaiman laments all the lost Norse tales that did not survive into modern times. I wish Gaiman had taken it upon himself to reinvent those lost stories rather than retell the known ones. All the stories were made up by somebody at sometime, why not tell new stories of Odin and Loki and the others?