Williams Electronics made their living with pinball machines but when the time came to break into the blossoming field of video games, they gave the task to Eugene Jarvis, designer and programmer of many groundbreaking and popular game platforms. He came up with Defender, a horizontal scrolling shooting game that was harder than it looked.

Jarvis finished programming the game in a fit of inspiration, just in time to unveil it at the Amusement and Music Operators Association convention. The game featured the player's spaceship traveling above a planet's mountainous landscape trying to protect several human inhabitants below from an alien attack coming from above. Other than enemy laser fire and missiles, the Defender craft had to be on the lookout for alien Landers that attempted to abduct the humans on the planet surface. That would be a very bad thing indeed because if a Lander got away with its human captive and made it all the way to the top of the screen, the two formed an alien-human Mutant that was much more powerful.

Other alien spaceships included the speedy, hard to target Baiters, mine-deploying Bombers, Swarmers attacking in undulating waves and Pods that turned into Swarmers after being shot. For his part, the Defender was armed with a beam weapon and a limited supply of smart bombs that could destroy every enemy on the screen. The Defender's weapons could also kill the very humans it was trying to defend so careful aim and a gentle touch was sometimes needed. If the Defender destroyed all the aliens and save at least some of the humans, play advanced to the next level.

An innovative feature of the game was the addition of a 'radar' function at the top of the screen which let a player know what was going on in the parts of the landscape he couldn't see. The radar allowed you to keep an eye on enemy movements and alerted you if a human was being abducted somewhere off screen. This was a revolutionary idea at the time but it wasn't enough to beguile convention attendees. Or rather, it was too much. Gamers thought that Defender was way too hard, with awkward controls (one joystick and five buttons) that were a hand cramp waiting to happen. The combination of multiple aliens firing at the player and others attacking the humans made for a multi-tasking nightmare.

Defender still caught on though, despite--or possibly, because of--its reputation for difficulty. Veteran arcade gamers who had mastered other games like Space Invaders were looking for a significant challenge and found it in Defender. It's still considered one of the hardest games out there, if you want to test your skills.