This is a great game with excellent graphics and sound that first appeared on the Spectrum but is now available in identical format for other machines.
Using alternate keys on the bottom row to move left and right, and any key on the third row to thrust him into the air, you must move your spaceman about the screen collecting three stages to build a rocket.
When you've done that you then have to fill it with fuel by collecting fuel pods as they appear from above. Once built and fuelled, the rocket will blast into space as soon as you enter it.
All this would be very easy were it not for the thousands of aliens who rush in from either side of the screen, intent on your destruction. You can get your own back by punching the fire button (or any key on the second row).
From time to time, valuable items (gold bars, isotopes and the like) will fall from the skies and grabbing them scores you extra points.
Once you've blasted away from the planet surface your ship rises to the top of the screen and then descends again, to land on another planet. Fighting off a different set of aliens you refuel once more, collect as much treasure as you can, and then blast off again.
This process continues until you get bored and switch the machine off, but I can assure you that that won't be for a very long time.