A Commentary is a verse by verse exposition of the Old Testament book of Genesis by Duncan Heaster, a Christadelphian missionary who writes from a one God, Unitarian, non-Trinitarian perspective. Issues of the creation record are discussed, the flood, the tower of Babel and character studies of Abraham, Jacob, Joseph and the tribes of Israel.
900+ pages, and regarding the length its quite normal for the commentary on the first book in the Bible. Well, regarding creation, there are many views out of there, it's impossible to made everyone happy with the view here, but its quite conservative and could be used as references.