Earth is destroyed by the heat of the sun and radiation. The Humans are forced to live in special domes because they are under constant attack from the Raak-Zun race. This race lives outside the dome. Then there is another race, Sentinels, who are known for destroying everything that gets in their way.

SunAge is a real time strategy game with a single player and multiplayer mode, and the possibility to play as one of the three different races. Each race has their own units, buildings and technological advantages and disadvantages. Goal of the game is to defeat the enemy by building different units. These units can be built with the 4 different resources: blue, green, yellow and red. Each building needs power to operate. Every player has one main power plant from which he can connect a series of pylons that link to the central power core.

Along the way, players can upgrade their units with an alternate mode. This option creates tactical depth in the game.