There's  an  easy  way  to  complete the three levels where T-800
battles  it  out  with T-1000 without losing any energy. Start hitting
the  fire  button  before the action starts and keep hammering away as
the two combatants appear. You hit T-1000 before he can shoot and when
he  gets  back  up  he gets hit by your next bullet. Keep firing until
he's  bashed off the right-hand side of the screen. On the final level
you have exactly the right number of bullets so don't waste any shots.