Easter Eggs
If you listen to the first six "intro" sounds in the sound test, listen for a few seconds after the instructions and normal reports. You will hear Tiny give you random useless facts ("Poison Arrow frogs are the world's most poisonous animals"), a "special voice mail from a very special little girl," and a hilarious recording of the game testers singing Tiny's "Tiny Boy" ending theme song.
Cowboy Hat
When you kill Big Bart in the first level his hat will be laying there waiting to be put on. If you get killed you will lose the hat.
Level select
Press and hold L1 + L2 + R1 + R2 + Left + Circle + Select at the new game Stamper menu
Cheat Code entry screen
Press and hold L1 + L2 + R1 + R2 + Left + Circle + Triangle + Square and press X at the options Stamper menu.
Low gravity
Enter FEATHER at the cheat codes screen.
View Game Over FMV
Enter "FMVUUU" at the cheat codes screen.
View Ending FMV
Enter "FMVVVV" at the cheat codes screen.
View Tiny Tank Music Video FMV
Enter "FMVWWW" at the cheat codes screen.
Invulnerability
At the Cheat Codes screen, enter TANKODOOM.