Defender

Defender was an arcade game created by Williams Electronics in 1980. It was designed and programmed by Eugene Jarvis (who later formed Vid Kidz and made more of Williams' hits), Larry DeMar, Sam Dicker, and Paul Dussault. This game was slow to become a hit when it was released as many thought it was too difficult due to its control configuration of five buttons and a joystick. It ultimately gained many fans and remained popular throughout the 1980s.

Gameplay:
The player flies a small spaceship above a long, mountainous landscape (in all versions, except the Atari 2600 edition due to memory limitations; in that case, the landscape consisted of a city represented by buildings). The land is inhabited by a small number of humanoids. The landscape wraps around, so flying constantly in one direction will eventually bring the player back to their starting point. The player's ship can fly through the landscape without being harmed by it.

A number of flying aliens reside in the air above the landscape. The player's responsibilities are twofold:
    1. Destroy all aliens;
    2. Defend the humanoids from being captured.

The player is armed with a beam-like weapon which can be fired rapidly in a long horizontal line ahead of the spaceship, and also has a limited supply of smart bombs (three, to begin with), which can destroy every enemy on the screen.

At the top of the screen is a radar-like scanner, which displays the positions of all aliens and humanoids on the landscape.

Initially the game was considered too easy, but the gameplay picked up considerably when 'baiters' were added which appeared after a set time period. The baiters kept the player under constant time pressure to finish the level, significantly increasing the intensity of the game.

At one point, when the game was nearly complete, the highest score anyone had ever managed was 60,000 points, and many people thought that this was a fluke. Indeed, the development team almost didn't add extra levels, as they believed that no one would be able to reach them.

Defender went on to sell more than 60,000 units — more than disproving projections — and cemented its place in video game history.