Metal Gear Solid
Sound menu:
Complete the VR training missions with a 100% ranking. The sound menu will be
unlocked at the options screen and allows all game sounds and music to be
played.
Special stage select:
Successfully complete the game under the "easy" or greater difficulty setting.
The special stage select allows any level to be played with new mission
objectives.
Plot Revelation:
Successfully complete stages in the special stage select to get No. 4 to reveal
pieces of the plot.
In-game entertainment:
Successfully complete the game, and then start a new game. Dial up 140.07 on
the Codec to hear some in-game entertainment.
