In each game in the series, with the exception of Captain Impostor, the player pilots a ship with the ability to be expanded by attaching 'modules' (such as lasers or boosters) gained from defeated enemies to a command module, represented by a box containing a broken heart. The goal in the game is to keep your ship alive for as long as possible. As the game progresses, stronger enemy ships (labeled according to letters from the NATO phonetic alphabet) arrive. Destroying stronger ships increases the Law (levels within the game), until Protectors (Peacekeepers in the original game) arrive to attack. The game effectively ends after the first Protector is destroyed (replacing the command module's broken heart with a complete one) but the player may continue accumulating parts indefinitely. If the player's ship is destroyed, it explodes, destroying all ships in the immediate area and clearing the area for the player to begin rebuilding their ship from scratch. The default background is a grid of green lines over a black background with a faint image of a pilot's face in the middle. The background can be changed, however, to an image taken by the player's webcam.
