Invincibility
You can still run out of fuel! Pause the game and press the following: LEFT, T, T, T ,T, UP, T, T, T, RIGHT, O, DOWN, X, T, T, T, S.

Passwords
5433 - This password sets first 3 missions as complete and opens missions 4 and 5
7154 - This password sets all missions and opens the final mission, called Area 51.

Cheats - pause game first
Max Fuel and Armor - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, T, T, T, O
Max Weapons (999) - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, R1, R1, R1, R1, L1, L1, L1, L1, R2, R2, R2, R2, L2, L2, L2, L2
Mesh Fog Editor - LEFT, S, S, S, S, UP, T, T, T, RIGHT, 0, DOWN, X, DOWN, DOWN, DOWN, T, T, T
Overhead Map Translucency - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, O, O, O, O, O.

Codes - pause games first
Cheryl Marie Boudreau Dance - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, DOWN, X, DOWN, X, DOWN, X, DOWN, X, DOWN, X
Debug Info - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, L2, R2
Overhead Camera - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, UP, DOWN, LEFT, RIGHT
Long Camera Views - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, X, X, X, O, X, X, X
Mission Complete - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, T, T, T, DOWN, DOWN, DOWN
All Missions Complete - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, SELECT, X, X, X, SELECT, T, T, T, SELECT, X, X, X
Enable Ground Crash - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, S, X, X, S
Turn off HUD - LEFT, S, S, S, S, UP, T, T, T, RIGHT, O, DOWN, X, R1+R2.