One by one, the invaders line up into a row while descending.
Game B: Scramble
The invaders descend with tricky movements that dodge missiles.
Game C: Storm
5 rows of invaders appear on screen that move horizontally back and forth across the screen as they advance toward the bottom of the screen. The player defeats an alien, and earns points, by shooting it with the laser cannon. As more aliens are defeated, the aliens' movement and the game's music both speed up. Defeating the aliens brings another wave that is more difficult, a loop which can continue without end.
Shooting an invader is worth anywhere from 10 to 30 points depending on shape, and UFOs are worth between 10 and 50 points.