A word of warning first! Crystal have been clever, the program has a special loader and instead of the usual interference lines in the border area while the game is loading it remains clear. You might be tempted to think that something has gone wrong and restart, but leave the tape running and all will be well. As the loading - continues, the game screen details are slowly built up to reveal the traditional appearance of a defender game.
Once loading is complete you are asked whether or not you have a Fuller box connected. If you have then spectacular sound effects are produced. Unfortunately, if you are not possessed of an amazing Fuller box, then the program is quite silent.
The game itself is a pretty classic copy of Defender.