Mission select:
Click Left Analog-stick, press Black, R, click Right Analog-stick,
press White, L at the mission selection screen.
Mission skip:
Click Left Analog-stick, press White(2), Back, click Right Analog-stick,
press White during a mission.
Alternate music:
Click Left Analog-stick(2), Right Analog-stick(2), press L, R at the
title screen.
Joke mission briefing:
Play missions 1, 3, 6, 8, 9 or 14, then press L(2), R(2), click
Left Analog-stick, Right Analog-stick at the armory screen before launch.
Sites: