Boss Survivial Mode and Extreme Difficulty

To unlock Boss Surival Mode and Extreme Difficulty, simply finish the game on any difficulty.

Bandana

To get the bandana, DO NOT submit to Ocelot's tourture and finish the game. The bandana gives you unlimited ammo while equipped.

Stealth Camouflage

To get stealth camo, submit to Ocelot's tourture and finish the game.

Tuxedo

For Snake to wear a tuxedo through the game, finish the game three times on any difficulty using the same save file.