Alien Nations is a real-time strategy game similar to The Settlers III. It features three campaigns à ten missions which are told from the perspective of one of the races: the blue stoneworking Pimmons, the militaristic and wild Amazons, or the insectoid Sajiki. The main focus lies on building a settlement with working production circles. Of course there are also other aspects which need to be taken care of, e.g. security or entertainment. So the player chooses the buildings he wants to construct and chooses a suitable place for it. The main source of income are taxes, which are mostly spent on balancing running costs - the rest can be used for research. Before the player can construct new or upgraded buildings he needs to meet certain research criteria.