Worlds at War: Conflict in the Cosmos is a 4x science fiction space navy combat simulation game along the lines of Reach for the Stars: The Conquest of the Galaxy. The player controls a fleet of space ships and bases, and proceeds to build ships, locate enemy bases, and take over the galaxy - or go down in defeat.

The game has an abstract board game style feel, but at higher difficulties adjacent regions can become more difficult to reach or even disconnected. Gameplay is always similar and in two dimensions, but the game setting can be selected as space or planetary seas for different difficulty levels and environment behavior.