Project Zomboid is available to pre-order; a zombie survival RPG, it features an open world with an isometric viewpoint where players can cooperate or compete to survive in the undead landscape. There should be demo in the near term (i.e., this month), but in the meantime, the site emphasizes that this is not a game you can win:
Project Zomboid is about the choices you make, and how you choose to live your last days on Earth. As a hero who goes out in a moment of heroic self-sacrifice to save a defenseless family? Or a callous coward who saves his own skin and leaves his companions for dead?
It’s these choices, and the story you weave in your adventure. That is what Project Zomboid is all about. Not saving the world with some pie in the sky cure, or flying away in a helicopter where everything will probably be okay. This is the apocalypse.
Here’s a crafting demo: