Zarch

The player, piloting a lone craft with limited firepower, must defend a finite landscape against ever increasing waves of enemy craft. In Zarch, the landscape is being invaded by aliens who are spreading a virus across the landscape. The seeder vessels are slow-moving, predictable, and easily destroyed, but as the game progresses they are supported by increasing numbers of flying support craft, which do not scatter virus but instead attack the player. The seeder vessels scatter red virus particles across the landscape. As they land, they turn the green landscape to brown and red, and cause the trees to mutate. Some flying enemies shoot the mutated trees, to cause themselves to become much…