Human

As Human you take control over a Country in europe or africa. Your job is to survive the Zombie attacks, advance through the ages and kill all Zombie Buildings and Units. Humans have to gather wood and gold in order to build Units and Buildings and to reaseach upgrades. They have one way to get gold and 2 ways to get wood.
 * Income

The main way to get gold and wood income is to build a foundation and upgrade it to a Lumber Mill in order to gain wood or to a Market in order to gain gold.

Another way to harvest wood is to chop down trees with a lumberjack.

Upgrading vs Massing Income Buildings To block out Zombies you need to place Buildings in gaps of the map to prevent Zombies from killing you. You gotta repair those Buildings with Workers or Robots.
 * Walling

Your Goal when placing anything as a Wall is to have the least space for Zombies attacking it, while having the most place for workers repairing.