That same year saw also saw the release of Stargate – Jarvis and Larry DeMar’s sequel to Defender. Like Defender, Scramble was ferociously difficult, particularly when the rolling planet surface gave way to claustrophobic little tunnels, where the environment became as deadly to negotiate as the waves of alien craft. The player’s ship traversed a rocky landscape, taking out alien craft with bullets and bombs while replenishing a constantly-falling energy supply by taking out fuel drums lying on the surface. Less mind-bogglingly fast than Defender, Scramble was clearly derived from the same DNA as Williams’ earlier hit. Just one year after Defender appeared in arcades, along came Konami’s Scramble. While Defender established Williams as one of America’s big names in game design – Joust and Robotron 2084 were two of its other major hits in the early 1980s – other developers were also looking closely at Eugene Jarvis’ breakthrough shooter.
As a result, Defender became one of the most popular games of the amusement arcade’s golden era, and the side-scrolling shooter was born. After the static screens of Space Invaders, Galaxian and their assorted clones, Defender’s speed and relentless intensity was mesmerising.