There has been a long line of "zap the disgusting aliens where it hurts" games. But despite the varied and complex plots, the action tends to differ little.

No doubt it is difficult for games developers to come up with enough variations on this well worn theme to ensure their creations are playable, memorable and capable of holding the attention for more than five minutes.

Two common approaches are used to overcome this problem. The "blind 'em with science" technique consists of stuffing the game with a bewildering array of hi-tech special effects and weaponry which require the dexterity of Paul Daniels to operate - "the mega neutron-disintegrator-meson-pulse-bomb is engaged by simultaneously pressing the Control and Escape keys while waggling the joystick with your toes."

The alternative is to ensure that the game looks good and maintains a balance between being too difficult for the majority of casual users while not being over simplified to the extent that boredom sets in rapidly.

Terrorpods is a hitech shoot 'em up that has adopted the latter approach, and is all the better for it. True, the plot runs along familiar lines - awesome Terrorpods are making life difficult for a colony, destroy all the Terrorpods in the colony's six sectors, collect a full set of Terrorpod components and deliver them to the Federation - but the gadgets and gizmos are kept to a minimum.

It is a visually attractive game. Two views are available - a control panel with a display of the view forward, and a plan view of the surrounding terrain.

Two weapon systems are available, missiles and a ground-to-air laser. As you move through a sector destroying the Terrorpods and their manufacturing units, you will come under attack from the Mother Ship.

A careful eye must be kept on the meters; run out of fuel and you can't move, run out of detonite and your weapon systems become inoperative.

Switching to plan view enables the Terrorpods to be located easily, however movement while in this mode tends to use up fuel at an alarming rate.

Control of your craft and of the weapons has been made difficult enough to ensure that it is not just a matter of point and fire. A good deal of concentration is needed.

This game breaks no new ground, and enjoyable to play.