UPDATE:The game is no longer Free to Play, it will split in 2 different games, H1Z1: Just Survive and H1Z1: King of the Kill. Anyone who already have H1Z1 will be granted both versions and will see it listed in Steam games inventory on February 17th 2016.
Offering a total sandbox experience, H1Z1 is a zombie survival MMO set in a post-apocalyptic world. H1Z1 is in EARLY ACCESS which means you should expect bugs and disruptions in service. Purchase if you’d like to help developers build this survival MMO game. It will be Free to Play when will reach full release status.