Here Micro Power has chosen a format which is simplicity itself, made it the simplest of games to use, and yet come up with what I think is one of the most amusing and compulsive games on the market today. Combine this with a highly colourful display, high scoring and wide age range appeal, and you have a winner.

What has happened is that a deadly Lepton has broken free inside a laboratory and is bouncing around inside. Luckily it cannot penetrate the walls or pass through the ion trail that you are about to lay inside.

To enter is certain death, so you employ a robot vehicle to do the work of laying the trail, and you sectionalise the laboratory, thus trapping the Lepton inside a small area.

If you cut off a small part of the laboratory but fail to trap the Lepton, you carry on until 95 per cent of the area has been covered, when the Lepton is eventually caught. This, however, reduces your bonus, which decreases as time passes.

If you do trap the Lepton it is a points bonanza and a big bonus to boot. But if the Lepton hits the robot vehicle or the ion trail before contact is made with another wall or another part of the trail, then it's one life lost.

As the game progresses little refinements are added, like chasers which follow your tracks. Needless to say, they are on the Lepton's side and contact with one costs you a life.

At one stage the Lepton multiplies itself and all are equally deadly. Then again it can move at double speed and you need to be very clever to outsmart it.

Your robot vehicle has two speeds. The higher means the less time spent in the danger area but fewer points.

A cool head, a steady hand and nerves of steel should ensure you a top score in this excellent game.