SDI (video game)
Encyclopedia
SDI - Strategic Defense Initiative, or simply titled SDI and sometimes known as Global Defense, is a side-scrolling shoot 'em up
arcade game
originally produced and released internationally by Sega
. It was later ported to home computers and game consoles, some by other companies. Players control a satellite
and must destroy enemies by moving a crosshair
over them and firing the satellite's weapons.
satellite orbiting the Earth and must destroy enemy missiles and satellites with its weapons, when activated the satellite's weapon systems fire at the crosshair
present onscreen during play. The arcade version features a joystick
to control the satellite and a trackball
to control the crosshair. Home computer versions use different control schemes, such as depressing the fire button to control the crosshair, alternating between controlling the satellite and its weapons. It is also possible to use a joystick
and mouse in combination to control the satellite and crosshair at the same time, emulating the arcade game's controls.
Each stage is split into two sections; offensive mode and defensive mode. During offensive mode the player engages a number of enemies, with the aim of destroying them all without the satellite being destroyed by the enemy. Should the player destroy all enemies during offensive mode, they are awarded 20,000 bonus points and begin the next stage on the offensive. If any enemies evade destruction during offensive mode, the player must complete defensive mode, where they are tasked with protecting the homeland from incoming warheads. Completion of defensive mode advances the player to the next stage, where they go on the offensive again.
This so-called "Star Wars" program was introduced by U.S. President Reagan to promote defensive weaponry that could shoot ICBM's out of space.
Shoot 'em up
Shoot 'em up is a subgenre of shooter video games. In a shoot 'em up, the player controls a lone character, often in a spacecraft or aircraft, shooting large numbers of enemies while dodging their attacks. The genre in turn encompasses various types or subgenres and critics differ on exactly what...
arcade game
Arcade game
An arcade game is a coin-operated entertainment machine, usually installed in public businesses such as restaurants, bars, and amusement arcades. Most arcade games are video games, pinball machines, electro-mechanical games, redemption games, and merchandisers...
originally produced and released internationally by Sega
Sega
, usually styled as SEGA, is a multinational video game software developer and an arcade software and hardware development company headquartered in Ōta, Tokyo, Japan, with various offices around the world...
. It was later ported to home computers and game consoles, some by other companies. Players control a satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
and must destroy enemies by moving a crosshair
Crosshair
A reticle is a net of fine lines or fibers in the eyepiece of a sighting device, such as a telescope, a telescopic sight, a microscope, or the screen of an oscilloscope. The word reticle comes from the Latin "reticulum," meaning "net." Today, engraved lines or embedded fibers may be replaced by a...
over them and firing the satellite's weapons.
Gameplay
Players control a Strategic Defense InitiativeStrategic Defense Initiative
The Strategic Defense Initiative was proposed by U.S. President Ronald Reagan on March 23, 1983 to use ground and space-based systems to protect the United States from attack by strategic nuclear ballistic missiles. The initiative focused on strategic defense rather than the prior strategic...
satellite orbiting the Earth and must destroy enemy missiles and satellites with its weapons, when activated the satellite's weapon systems fire at the crosshair
Crosshair
A reticle is a net of fine lines or fibers in the eyepiece of a sighting device, such as a telescope, a telescopic sight, a microscope, or the screen of an oscilloscope. The word reticle comes from the Latin "reticulum," meaning "net." Today, engraved lines or embedded fibers may be replaced by a...
present onscreen during play. The arcade version features a joystick
Joystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
to control the satellite and a trackball
Trackball
A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a cursor...
to control the crosshair. Home computer versions use different control schemes, such as depressing the fire button to control the crosshair, alternating between controlling the satellite and its weapons. It is also possible to use a joystick
Joystick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or...
and mouse in combination to control the satellite and crosshair at the same time, emulating the arcade game's controls.
Each stage is split into two sections; offensive mode and defensive mode. During offensive mode the player engages a number of enemies, with the aim of destroying them all without the satellite being destroyed by the enemy. Should the player destroy all enemies during offensive mode, they are awarded 20,000 bonus points and begin the next stage on the offensive. If any enemies evade destruction during offensive mode, the player must complete defensive mode, where they are tasked with protecting the homeland from incoming warheads. Completion of defensive mode advances the player to the next stage, where they go on the offensive again.
This so-called "Star Wars" program was introduced by U.S. President Reagan to promote defensive weaponry that could shoot ICBM's out of space.