Moon Shuttle

Aliens have invaded our asteroid belt! It’s up to you to get rid of them. Your
space ship on the bottom of the vertically scrolling screen dodges and shoots
at asteroids, hostile ships and the like. By moving left and right and firing
rapidly, first you must clear a path through the asteroids. Only then you can
take on the alien craft. Pushing up on the joystick increases speed, but
crashing into an asteroid means death. A bonus is awarded if you pass through
unscathed. Once on the other side, the aliens attack from the top and sides of
the screen and drop missiles. The first wave is just a teaser. Progressive
waves are more aggressive and harder to kill. If you destroy a certain number
of aliens, more asteroids must be avoided or destroyed, followed by yet
another alien attack, and so on, until eventually all are defeated or you have
no more lives.