Sega Master System / Mark III / Game Gear
You are probably familiar with SDI from the arcades, it is a Missile Command deriviative with a fast almost compulsive feel to it. The scenario has you sitting in a Global Defense Satellite high above the Earth you have to shoot down missiles, satellites and Crab Ships which are trying to blow up Earth.
To stop them you control the Satellite and a cursor sight, button 1 and the joypad moves the satellite while joypad and button two sight and fire interceptor missiles.
The game has ten stages, five offensive and five defensive (Earth, Moon, Asteroid Belt, Saturn and Hidden Planet). You have three lives with a life being lost if you are shot by the enemy.
You are faced with an Offensive half to start with, if any missiles pass you have to play a defensive half destroying the missiles before they enter the atmosphere and hit the planet (the damage meter is carried over).
You start against a smooth scrolling backdrop of space (left to right) and missiles fly in from the right side of the screen.
SDI is a quality game with a good feel and enough action to keep you away from the TV. Firing into a cursor takes a little getting used to but when you do...