How to Get the Big Boss Emblem in Metal Gear Solid 4

Start a new game in Boss Extreme mode. You must first complete the single-player game in Normal mode. Once you have done this, Boss Extreme mode will be available from the main menu.

Use "iPod Healing Music" if you need to heal. Avoid using any items that instantly replenish your health, or you will be disqualified from receiving the emblem.

Use non-lethal attacks against human opponents. You can stun opponents, put them to sleep or otherwise injure them, as long as you avoid killing them. The goal is to play through the entire game without killing a single human opponent.

Remove any special items, such as the Bandanna or Stealth Camo, from your Items so that you don't accidentally use them.

Crawl and use items such as Chaff Grenades and OctoCamo to avoid triggering alerts.

Play through the game without using any continues.

Beat the entire game in five hours or less while following the above rules.