Annihilator is a single player Defender clone. The player pilots a small space ship over the surface of a rocky planet. The objective is to shoot alien space ships and achieve a highscore. Once all aliens have been cleared from the screen the game pronounces 'SECTOR CLEARED' and the player progresses to the next level. Levels become progressively harder as the game continues. Screen one has just airborne alien ships, screen two has ground installations, screen three has random meteors which must be avoided and so on. Apart from the single shot front firing canon the player starts with a 'smart bomb' and can earn more. An extra space ship / life is earned after 10,000 points. A joystick is required to play this game.