Astro Patrol

Astro Patrol is a science-fiction themed arcade game for the VIC-20.

The player controls a spaceship which moves in the 4 cardinal directions. The player's ship has a laser gun which shoots to the right of the screen. Alien vessels stream from the right. Every alien vessel that bypasses the player awards points to the aliens, while the player receives points for shooting down alien vessels. At 1000 points, the player starts wave 2, which has alien vessels moving in more complex patterns, and the player is accompanied by a second vessel.

The game ends at 2100 points, where the final score is the difference between the player's and aliens' scores.