The Boss Extreme Difficulty Video Walkthrough

Zero kills, zero alerts, zero recovery items, new save file (i.e. no inherited items)

Note: If you're going for the Big Boss emblem, following this guide will leave you with more than enough time to spare. My total playtime was 11 hours and 42 minutes, the game has around 8 hours of cutscenes, and watching cutscenes adds to your total playtime.

Intros

Bomb Shelter Buffet
Celebrity Moralist
Ocean of Gossip
The Circle
Body of Armor
Opening
Three Days Earlier
Mission Briefing Part 1
Mission Briefing Part 2

Act 1 - Liquid Sun

Octacon(Cutscene)
Red Zone NW Sector
Red Zone
Metal Gear MKII(Cutscene)
Red Zone pt II
Militia Safe House
Drebin(CutScene)
Drebin(Cutscene) Part 2
Urban Ruins
Downtown
Advent Palace(Going Up + Cutscene) Part 1
Advent Palace(Going Up + Cutscene) Part 2
Advent Palace(Going Up + Cutscene) Part 3
Advent Palace(Escape)
Advent Palace(Rat Patrol 01 Cutscene)
Advent Palace Garage
Four Terrors(Cutscene)
Millennium Park
Liquid(Cutscene)

Act 2 - Solid Sun

Act 2 Mission Briefing
Solid Sun Intro
Cove Valley Village
Cove Valley Village(Cutscene)
Cove Valley Village(Rebels)
Power Station
Drebin(Cutscene)
Power Station Part 2
Codec Call(Cutscene)
Confinement Facility
Vista Mansion
Naomi(Cutscene)
Naomi(Cutscene Part 2)
Research Labs-Frogs
Laughing Octopus/Boss Battle
Octopus(Cutscene)
Octopus-Human Form
Drebin Explains It All(Cutscene)
Tracking Naomi(Cutscene)
Mountain Trail
Mountain Trail(Cutscene)
Drebin Getaway
Raiden Cutscene
Marketplace

Act 3 - Third Sun

Mission Briefing
Opening Cutscene
Midtown S Sector
Midtown Central Sector
Midtown NW Sector
Midtown NE Sector
Midtown N Sector
Big Momma's House(Cutscene Part 1)
Big Momma's House(Cutscene Part 2)
Motorcycle Chase Part 1(Church Courtyard)
Motorcycle Chase Part 2(Riverside West)
Motorcycle Chase Part 3(Riverside East)
Raging Raven Intro(Cutscene)
Raging Raven/Boss Battle
Raging Raven Human Form
Closing Cutscene Part 1
Closing Cutscene Part 2
Closing Cutscene Part 3

Act 4 - Twin Suns

Mission Briefing Part 1
Mission Briefing Part 2
Shadow Moses Retro
Snowfield
Nuclear Warhead Station
Nuclear Warhead Storage
Crying Wolf Intro
Crying Wolf/Boss Battle
Crying Wolf Human Form(Cutscene)
Time to Swap Discs(Cutscene)
Blast Furnace
Casting Facility N + S
Underground Base + Vamp Intro
Vamp/Boss Battle
Suicide Geckos
Rex is Alive(Cutscene)
Surface Tunnel
Rex vs Ray
End Cutscene

Act 5 - Old Sun

Mission Briefing
Ship Bow
Frogs Intro(Cutscene)
Frogs
Screaming Mantis Intro(Cutscene)
Screaming Mantis/(Boss Battle)
Screaming Mantis Human Form
Missile Hanger
Microwave
GW(Cutscene)
Snake vs Liquid(Cutscene)
Snake vs Liquid FIGHT/Boss Battle
Game Over Man,Game Over(Cutscene)

Epilogue - Naked Sin

Marriage
Raiden & Rose
Snake in the Graveyard
Drebin Explained
Credits....Psyche!!!
Big Boss
Credits & Final Results