Begin With 99 Ships
At the One Player/Two Player screen, press and hold L and R on
Controller One. Hit Select and Start on Controller Two. Begin the
game, and the number of ships shown in the lower-left corner will
read 49.
Altered Demo
Play the game until you achieve the high score (over 100,000 points). At the Hi
Score screen, enter the initials ZZT. Let the demo run, and you'll see
interesting changes.
Easy Passage
Position your ship at the top of the screen above the last three digits of
the score. You'll fly through Stage 1 without taking damage.