By the year 3000 AD, the human race had progressed almost to the point of perfection. With no more poverty, war, or discrimination, the worries of mankind seemed to be over.
But the human race had created a new crisis for themselves. They had no idea how to defend themselves, or how to survive a major holocaust -- the long period of peace had diminished their survival instinct. The United Earth Government decided that they needed to stimulate this instinct in the people, to revive their will to fight for their lives if the need arose. So they developed an awesome simulated war environment, run by a super computer -- the Gain Ground system. 
However, something went wrong while testing the system. It refused all input and went berserk, and all of its creators became its captives. The government sent a rescue party, but they too fell captive to robotic soldiers. After several more futile attempts, one last rescue party was assembled -- but if this one failed, then the entire system-world would have to be destroyed. 
Three brave soldiers, carefully selected for the last attempt, have entered this vast, hostile battleground -- determined to survive and to save their fellow man.