Neptune: Neptune's Net

You'll land on the ground without any weapons except your knife. You'll also be separated from Mother for the time being. For now, you'll need the element of surprise to survive.

Start by turning on your night vision and using prone mode to crawl through holes. you'll locate a lone bad guy that can be defeated with a knife swipe. He's drop a basic rifle you can use to take done more enemies. Continue to remain quiet and kill the patrol guards with quick headshots.

As long as you remain hidden and take out enemies quickly, no one will detect your presence. When a second patrol arrives, hide behind the rocks up the hill to the right. Eventually you'll hook up with Mother who will provide you with some better weapons.

Continue to move quickly with Mother and take out only the enemy forces that get in your way. Many of the ground enemies will be distracted by your air support, so you can simply ignore them to save time. Eventually you'll be wounded and unable to move. During this time Mother will help carry you and you'll only be armed with a pistol. Gun down and protect Mother as he tries to take you to safety. After some time, the mission will end.