"Doodle God" is not so much a game as it is a gigantic mix-and-match puzzle. You begin the game with four elements -- earth, fire, air and water -- and you combine those elements together to create new elements. As new elements are created, the number of possible combinations increase, and become increasingly more difficult to figure out. Humans are also considered an element in "Doodle God," and can be created by mixing two other elements together. In order to create Humans, you must have already discovered and mixed the "Swamp" and "Energy" elements to create the "Life" element.
Mix together the "Lava" and "Air" elements to create "Stone," then mix "Stone" and "Water" to create "Sand."
Combine "Sand" and "Swamp" to create "Clay," then put together "Clay" and "Life" to create the "Golem" element.
Select "Golem," then combine it with "Life" to create the "Humans" element.