Early history of video games
The history of video games spans a period of time between the invention of the first electronic games and today, covering a long period of invention and changes. Video gaming reached mainstream popularity in the 1970s and 1980s, when arcade video games, gaming consoles and home computer games were introduced to the general public. Since then, video gaming has become a popular form of entertainment and a part of modern culture in most parts of the world. The early history of video games, therefore, covers the period of time between the first interactive electronic game with an electronic display in 1947, the first true video games in the early 1950s, and the rise of early arcade video games in the 1970s ("Pong" and the beginning of the first generation of video game consoles with the Magnavox Odyssey, both in 1972). During this time there were a wide range of devices and inventions corresponding with large advances in computing technology, and the actual first video game is dependent on the definition of "video game" used.
Space Invaders
As one of the earliest shooting games, "Space Invaders" set precedents and helped pave the way for future titles and for the shooting genre. "Space Invaders" popularized a more interactive style of gameplay with the enemies responding to the player controlled cannon's movement, and was the first video game to popularize the concept of achieving a high score, being the first to save the player's score. While earlier shooting games allowed the player to shoot at targets, "Space Invaders" was the first in which targets could fire back at the player. It was also the first game where players were given multiple lives, had to repel hordes of enemies, could take cover from enemy fire, and use destructible barriers, in addition to being the first game to use a continuous background soundtrack, with four simple diatonic descending bass notes repeating in a loop, which was dynamic and changed pace during stages, like a heartbeat sound that increases pace as enemies approached.