RAID (1K ZX81)
by C G Brown, Sutton Coldfield, West Midlands
from Your Computer (December 1982), Page 97

When the game starts, you must press 0. When you release 0, your missile
will rise to the top of the screen. It will then reappear at the bottom of
the screen. The object is to shoot each invader, so you have a high score
when the invader finally reaches the bottom of the screen. You must not
press 0 after your missile has passed the Graphic Shift 7s, or the game
will stop. The game takes a fair amount of practice, before you know
exactly when to release your missile, represented by an *.
