Stealth and Bandana:
Complete the Tanker mission three times on three different difficulties (all on the same saved file) and get all the dog tags.

Stealth and Wig:
Complete the plant three times on three different difficulties (all on the same save file) and get all the dog tags.

Sunglasses:
After completing the game twice, Snake and Raiden will be wearing sunglasses.

European Extreme difficulty:
Complete the game on the normal difficulty setting.

Boss survival mode and Casting Theater option:
Complete Sons Of Liberty on any difficulty setting.

Photograph mode:
Complete bomb disposal mode, hold up mode (alternative missions), and eliminate mode to unlock photograph mode in the VR Missions.

Ninja Raiden:
Complete 50% of the VR missions as Raiden to unlock Ninja Raiden in the VR Missions.

Raiden X:
Complete 100% of the VR missions as Raiden and Ninja Raiden.

Pliskin:
Complete 50% of the VR missions as Snake.

Tuxedo Snake:
Complete 100% of the VR missions as Pliskin.

Metal Gear Solid 1 Snake:
Complete 100% of the VR missions as Snake, Pliskin, Tuxedo Snake, Raiden, Ninja Raiden, and Raiden X.

Control title screen:
Press White to hear a gunshot and see a flash at the title screen. Use the Right Analog-stick at the title screen to change the background color.

Digital camera:
Complete the game. The digital camera will be available when a new game is started. It is found in Strut E Shell 1. Go to the bottom of the screen and locate the platform with three red lights on it. Climb up onto it and equip the Z.O.E. Box. When the conveyor stops, press Action to climb on. You will be taken to another room. Press Action again to get off and retrieve the Digital Camera. Exit the room in the same fashion.