Watch “Invasion: Earth (GDW) Review & How to Play,” a how-to-play guide for Invasion: Earth from Tabletop Sci-Fi on BoardGameVideo.
Description provided by Tabletop Sci-Fi on YouTube:

1981John Astell, Frank Chadwick, Marc W. Miller
About Invasion: Earth, from BoardGameGeek:
Designers
John Astell, Frank Chadwick, Marc W. Miller
Artists
Paul Richard "Rich" Banner, Naoyuki Kato, William H. Keith, Jr., Chris Purcell
Publisher
Game Designers' Workshop (GDW Games)
Categories
Mechanics