There are some buildings designed to give you a source of income. There are others used to defend your base and/or create units.
Building Purposes Edit
These buildings main purpose is to make units. Production buildings are the following:
These buildings are used to protect an area or unit. Defensive buildings are the following:
There are certain buildings that can help defend and produce income or units. The Fusion Plant has a Light Turret equipped onto it and could also increase the income for the player by 20p. The Headquarters has 4 Heavy Turrets equipped onto it and could also produce the almighty Mobile Fortress. The Research Center has a Turret on it as well, while it can produce Gunships and RPG Soldiers. The Fort has 2 turrets too and could produce the Humvee, Jeep, Artillery, and the Juggernauts. The Command Center doesn't produce anything, but it has 2 turrets on it too, and has the ability to garrison units.
There a three land based buildings that will give you income. They are the Power Plant, Nuclear Plant, and Fusion Plant. Put them next to the green crystals around there map. You can only place 1 type of Plant by each crystal. Along with the land buildings, there is an Oil Rig that can be placed by the Oil Ship on top of oil spots (black clouds on the water).