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SDI: Strategic Defense Initiative is based around classic-style shoot 'em up action. It puts you in control of a satellite which must ensure that the wave of bombs aimed for the United States do not hit. Direction of motion and direction of fire are controlled independently - on the 16-bit versions you rotate the mouse left and right to direct the targeting, move it up and down to increase the range, and use the joystick to move the satellite and thus avoid any contact.

Each level is split into defensive and offensive stages. On defensive levels you must stop each unit as it heads towards the earth, a lá Missile Command. Offensive stages follow the old 'shoot it before it becomes a danger' philosophy, being free-flying shoot 'em up sections among a network of destructible (but worth saving) platforms.


SDI: Strategic Defense Initiative Atari ST Game over
SDI: Strategic Defense Initiative SEGA Master System Defend the planet against missiles
SDI: Strategic Defense Initiative Atari ST Game start
SDI: Strategic Defense Initiative Commodore 64 I was hit and destroyed.

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Alternate Titles

  • "SDI - Now The Odds Are Even" -- Spanish title
  • "SDI" -- Official abbreviation
  • "Mobile SDI" -- Mobile Sega Ages title
  • "Global Defense" -- SEGA Master System title

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Critic Reviews

Computer and Video Games (CVG) SEGA Master System Apr, 1988 8 out of 10 80
Sinclair User ZX Spectrum Jul, 1991 70 out of 100 70
Power Play SEGA Master System Apr, 1988 6.5 out of 10 65
Your Sinclair ZX Spectrum Jul, 1991 64 out of 100 64
Commodore Format Commodore 64 Jun, 1991 64 out of 100 64
ACE (Advanced Computer Entertainment) SEGA Master System Nov, 1988 618 out of 1000 62
Atari ST User Atari ST Feb, 1989 6 out of 10 60
The Games Machine (UK) Amiga Sep, 1989 57 out of 100 57
Tilt SEGA Master System Mar, 1988 8 out of 20 40
Game Freaks 365 SEGA Master System 2000 3.5 out of 10 35


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Contributed to by chirinea (39847), Martin Smith (62867) and LepricahnsGold (123886)