Space Invaders

Space Invaders
Space Invaders is an arcade game published by Taito Co., Ltd. in 1978. Space Invaders is the biggest hit in the history of arcade games and the earliest example of a shooting game. Similar products and bootlegs have been made by other companies such as Irem's IPM Invader.

Gameplay Overview
Space Invaders is a one-button game with a 2-way joystick. The beam cannon can only move left or right, fire is limited to one shot and cannot be fired again until it hits somewhere.

There are several protective walls (pillboxes) behind which the player can hide, over time these walls will be destroyed either by the invaders or the player. A total of 55 invaders descend from the top, their movement increases as their numbers decrease and it becomes more difficult to hit them. If the invaders manage to get to the bottom then the game will be over no matter how many lives are left.

Controls

 * 2-way Joystick: Horizontal movement
 * Button (Press): Fire

Scoring

 * Large Invader : 10 points.
 * Medium Invader : 20 points.
 * Small Invader : 30 points.
 * UFO : 50 to 300 points.

UFO scoring technique
The score of a UFO is not based on any random number, but rather it is controlled by the number of shots fired. The UFO is worth 300 points if hit with the 23rd shot and on every 15th after. At the start of the game count 22 shots, when the UFO appears fire the 23rd shot at it, you will get 300 points, now count 14 shots and fire the 15th shot at the UFO, again you will get 300 points, following this pattern every UFO on 15th shot will be worth 300 points.

"Nagoya Shot"


The invaders do not generate their attack directly below them, but rather at a distance of one row, this makes it possible to slip under when the invaders reach the bottom row close to the cannon. This strategy is named after the city in Japan where it was presumably discovered.

A common use of these strategies is to destroy 4 collumns on the left and 2 collumns on the right, leaving a group of five on the right and one invader in the upper left corner, this creates a narrow space in the formation where the beam canon can stay out of invaders' attacks so UFOs can be destroyed safely for extra points, and when the invaders reach the bottom they can be shot up close.

video showcasing these strategies https://www.youtube.com/watch?v=Ty2z6KP5X0Y

Trivia


June 16th is officially recognized as the "Space Invaders Day".