I read this with my dragon-curious eight year old, who enjoyed the illustrations very much and mostly stayed with the stories, particularly enjoying anything involving Thor and Loki.
The myths, most of which I was at least vaguely familiar with, are simplified and moderately sanitised for a younger audience, but retain the warmth and humour present in longer versions. The Norse, to their great credit, seem to have taken their gods a whole lot less seriously than other civilisations.
Far from a definitive edition, but an enjoyable, nicely paced child-friendly introduction to Asgard and its denizens.