Torus Trooper is a indie 3D tunnel shoot-em-up (a gameplay style originating with games like Tempest (1981)). The player pilots a ship down the inside of a continuous tunnel, shooting other ships. After a certain number of enemies have been destroyed, a "boss" ship appears, the destruction of which adds time to the player's diminishing timer. When the timer reaches zero, the game ends.
The game contains several difficulty modes, and was written in the D programming language.