Cheat mode
Begin game play, eliminate the first two aliens and
enter the room from which they emerged. Then, enter one of the
following codes to activate the corresponding cheat function.
Level select
Hold [L1] + [L2] + [R1] + [R2] + [Triangle],
then intentionally lose. Keep the buttons held through the ending
FMV sequence. A green light will confirm correct code entry. A
new starting level from 1 to 16 may now be selected at the opening
screen.
Unlimited energy
Hold [L1] + [L2] + [R1] + [R2] + [X],
then intentionally lose. Keep the buttons held through the ending
FMV sequence. A blue light will confirm correct code entry.
All weapons with unlimited ammunition
Hold [L1] + [L2] + [R1] + [R2] + [Circle],
then intentionally lose. Keep the buttons held through the ending
FMV sequence. A red light will confirm correct code entry.