The first issue sets the tone as he mirrors the structure of the movie (in a 17 page comic!). We first meet a caveman who is a small step above his bestial companions, and in meeting the monolith, learns to create the first edged weapon. We switch to the future where his supposed descendent is trapped on the moon... Issue two follows the same structure with a female protagonist. The highlight of these two issues is getting a Kirby story of ancient man, and then followed up by Kirby's version of the Kubrich future. His art is powerful, and while I'm not the biggest fan of Royer's inks (I feel he followed Kirby's pencils a little TOO slavishly, rather than bringing his own influence to them like a Joe Sinnott or Joe Simon did), Kirby's art is strong, filled with action and does an incredible job of leading the reader from panel to panel.
Issues three and four are a leap forward as he leaves behind the format's structure and tells the story of Barak who uses the knowledge from the monolith to create the world's first army. Kirby is at a peak here with some incredible two page battle sequences, wonderful end of page reveals and excellent pacing. We also go from fearing Barak's barbarianism to understanding his shift from brutal leader to a man who is bringing humanity forward in his own drive for both conquest and love. It shows that Kirby really enjoyed the fantasy/prehistoric style adventure he did in Kamandi, and his...well...quirky dialogue works perfectly in this type of story (as it did in The New Gods).
It was not a huge hit at the time, and I see it as some of Kirby's most under-rated work.