| Commodore VIC-20 |
· There’s a trick to stay on the first screen forever. To do it, you'll need at least 2 ships. Shoot all the invaders except the ones in the upper-left and upper right corners. Keep your ship centered between them as they move down, but stay on the bottom of the screen. When they reach the bottom, you'll lose a ship. Immediately push up and center your ship. The remaining invader will move across the bottom of the screen from left-to right (at the same height your ship was at when they landed) and eventually wrap-around the screen. As long as you stay above it, you can shoot Gorfs and saucers forever. {Jeff Bruette}
· One of the earliest games to include copy-protection code.
