There aren't wenough serious games about the stoneage period. Prehistoric tribes are so underrated. Granted they weren't the philosphers, inventors and empire builders of later ages, but they weren't just the eat/run/hit types that they are steroetyped as. Everything we have today, we ultimately owe to these people.
The only problem I had with your game were your mission breifings. The pronoun only useage made them a little hard to read. I'm guessing they were written that way so that we would see your characters as representatives of the prehistoric period overall instead of just one or two individual tribes. Still, proper names would clear some of the confusion.
Everything else was well done. I was able to lose myself completely in the world you created. Your narration wasn't lost on me. Early man survived through conflict. Adapt or die. The world of modern man isn't too far removed from this. When you think about it, the only things that have really changed btween now and then are the toys and the articulation. We may live in a world of technologic wonders where massive ammounts of information are available to all, but we still have the same hopes, desires and fears as our ancestors. We still ask the same questions as we struggle to undertsand the world while we try to make a place for ourselves in it. Are we really so far removed from those of ages past?