Set in the distant future, this science fiction strategy was inspired by Total Annihilation (1997) and is designed by one of the original game's engine creators, Jon Mavor. Planetary Annihilation gameplay is largely similar to classic RTS series like Starcraft or Command & Conquer, yet not without its own unique features. This game is focused on interplanetary wars on a larger scale and allows its players to conquer the whole worlds or even destroy them using nukes and Death Star-like devices. The maps are randomly generated, and each map constitutes a whole planet in 3D projection (albeit scaled down). Each player starts with a Commander unit that is used to create necessary buildings. Commanders represent the player and, like in chess, loss of your Commander means losing the game.

The definitive feature of the game is that battles are not contained to certain planets, but are fought across the whole planetary systems using missiles and "planet thrusters"; and there are many such systems in the galaxy. The scale of the setting can make it difficult to keep track of one's operations across different systems at the later stages of the game.