At anytime during gameplay enter "Left Thumbstick, White, White, Back, Right Thumbstick, White".
At the armoury screen before launching missions 1, 3, 6, 8, 9, or 14, press L(2), R(2), click Left Analog-stick, click Right Analog-stick.
At the front-end, click Left Analog-stick(2), click Right Analog-stick(2), press L, R.
At the mission selection screen, click Left Analog-stick, press Black, R, click Right Analog-stick, White, L to unlock everything.
The flak cannon works well at close range. Fire it at the first group of landing craft then use your pistol for the tanks at long range.
While playing a mission, click Left Analog-stick, press White(2), Back, click Right Analog-stick, White.
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