Scooby Doo! - Night of 100 Frights:
During gameplay press pause, then hold all four shoulder buttons and enter the codes:
All Power-Ups:
Circle, Square, Circle, Square, Circle, Square, Square, Square, Circle, Circle, Square, Circle, Circle, Circle.
Unlock All FMV Sequences:
Square, Square, Square, Circle, Circle, Circle, Square, Circle, Square.
View Credits:
Square, Circle, Circle, Square, Circle, Square.
Holiday Bonuses:
Change the PlayStation 2 system date to the following entries for some special seasonal decorations:
December 25 - Snow.
January 1 - Fireworks.
July 4 - Fireworks.
October 31 - Giant Bats.