The first "slide-and-shoot" game, Space Invaders has players piloting a laser base that moves right and left along the bottom of the screen, firing upward at descending aliens. Each wave of invaders consists of 55 enemies grouped in 11 columns, moving in unison horizontally, and dropping a level each time they reach either side of the screen. The player's job is to destroy the invaders before they reach the bottom of the playfield. Eliminating the Mystery Ship that flies intermittently over the top row of invaders will earn the player Bonus points. Positioned across the lower section of the screen lie four bunkers, under which players can hide. However, the bunkers erode piece-by-piece when shot by enemy or friendly fire. In addition to being the first of its type, Space Invaders was the first game to post a continuous high score (assuming no one unplugs the machine). Other groundbreaking features include menacing sound effects, addictive gameplay and a high degree of character design and animation. The game was enormously popular, with more than 60,000 machines sold in its first year of production in the U.S. It was such a hit in Japan that it caused a shortage of the 100-yen piece used to play the game. ~ Brett Alan Weiss, All Game Guide
