Two players take turns in placing items in the game world. Items either attract animals, or drive them away. They try to get 2 animals together, either to make them mate, or to make one eat the other. Each player has a limited number of items, and both players have conflicting goals. The goals always relate to the animal population. Whoever fulfills his goal better wins.

Players can select from their available items, and place them in the game world. This works entirely by mouse (or could work with a touch-screen). If the game world does not fit into one screen, then players also can scroll across the game world.