EARTH DEFENCE, for the 16K Spectrum, is a fairly faithful reproduction of the arcade game Missile Defence. In it you must defend your cities and missile sites from invading nuclear missiles and other craft.
You have three missile batteries from which to fire and a controllable cross-hair sight. Timing is all-important. You have a limited number of missiles and time must be allowed for them to reach their destination. If you survive the first wave of attackers your score is totalled according to how many cities and missiles you have remaining and another wave appears. Bonus cities are given every 1,000 points. The game has three levels of skill and can be played by one or two players, there is also provision to use either a Sinclair or Kempston joystick or the keyboard.
The graphics are adequate for this kind of game, although the sound is rather limited during the explosions.