In the first part, you explore the building Trautman could be in, through a top-down view of the building. It is heavily protected by infra-red security beams, which when activated unleadsh the enemies. The locations of the beams are only apparent if you collect the special goggles. Other hazards include mines, trapdoors and booby-trapped doors, but there are enhanced weapons to collect.
Section two is identical to the first, except that it is located outside, the enemy are onto you from the start, and there are no traps. The final section changes to an Operation Wolf-style shoot 'em up, with a horde of tanks, foot soldiers and helicopters to face. Your gun can jam, which adds to the challenge of finally getting out alive.