This package consists of two programs. The first is an introduction, explaining the main rules of the game, and the second is the main program.

This starts by asking for the user's name and explaining the scoring.

The user then becomes commander of a protector ship with a mission to exterminate aliens from 10 sectors of space. The first task is a tedious space scan to detect the mother alien ship.

The game now begins by the mother ship attacking with four consecutive waves of different aliens. The protector ship, which can be moved from left to right using the arrow keys, must destroy the aliens by shooting darts from below.

Each alien destroyed from the first wave counts 10 points, from the second 20, 30 from the third and 40 from the fourth. Once all these aliens have been destroyed, the mothership must be eliminated.

After refuelling and a further space scan the process is repeated until all ten sectors of space are free of aliens. The score is displayed during the game and at the end is incorporated into an honours list.

Although the game may at first appear repetitive, it is well presented and challenging.

R.S.