Play through the game to achieve Big Boss rank at the end. Playing on Original difficulty is required for this rank.
Save time by opening the elevator first before getting the level 1 door card.
*Hind D takes 4 missiles to destroy
No Alert - Non Lethal Box Pick Up example
https://clips.twitch.tv/BitterAbrasiveHerdCharlieBitMe-1aJGzl9yGMEXtQju
If you want to practice 4F Mannequin Room, you can enter and exit the rooms to get different RNG seeds
Ideal Spot to go up in Mannequin Room
After the Night Fright fight you can press the elevator before moving on to save precious time:
to Underground Base