Facing this crashing vote, I feel that I'm in for some stoning by giving this Maiden standard only four and a half. The reason is that for some reason I never became really fond of the main riff and the chorus.
What grabs me, however, is the instrumental part, everybody's favourite. I love the soft (as in "Finally the fury stops for a while") bass driven intro to what I think is the most beautiful solo by Dave ever. (The version on Life Atfer Death has that special something - the extra drumming when Dave starts. As for the main riff, that sounds better live too, due to rawer guitar sound.) The two quick solos and the superb bit in between are really grinding. This is just breathtaking musicianship.
The commentary on the Egyptian theme is interesting. I especially liked the total eclipse of the sun seen as the eye of god. As for the lyrics, I found this verse puzzling:
When the Life-Giver dies, all around is laid waste
If this is given and the Egyptians really believed in the deity of the pharaohs, I wonder how they accounted for the fact that the world goes on after the ruler dies.