Crash Bandicoot 2

Colored Gems
Here's how to get all the colored gems
Turtle Woods (Blue): Get no boxes.
Snow Go (Red): Look at secret warps, get the one for Snow Go.
The Eel Deal (Green): Go past the dead end in the Nitro box filled room.
Plant Food (Yellow): Get no boxes and beat the timer.
Bee-Hauling (Purple): Go up the stairs of Nitro boxes.
Extra Lives
In the second warp room, go to the barking bear and jump on him until 10 extra lives come out of him.
 This can only be done once.
Hidden Warps
Bear Down: The small ice float at the end of the stage.
Air Crash: The 2nd river, don't jetski, but jump on the boxes to the platform.
Unbearable: When the cub bucks you off, go back until you see him again.
Hangin' Out: When you drop down a hole into some eel-less water, go into the foreground and drop down the hold.
Diggin' it: Near the end there is a spitter plant on a circular platform. Bellyflop onto it.
Boss Warp:
To go to the next or previous boss, press and hold L1, L2, R1, R2, and Triangle when standing on the middle platform of a warp room.

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 Crash Bandicoot 3: Warped

Spyro the Dragon Demo
At the Title screen, press Up, Up, Down, Down, Left, Right, Left, Right, Square.
Secret Level 31
In Road Crash level, take out the alien sign on the left side about halfway through the race.
 5 Extra Lives
In level 11 take the yellow gem ride. Double jump over the yellow gem.At the end double jump over the steel wall.
 Bonus Levels
To get to the Bonus Levels you must complete each time trial and getthe relics for it. It requires 5 to go to the bonus.
Level 32
Get the yellow gem from the Hang 'Em High secret entrance, then go to level 11 (Dino Might!) and use the yellow gem platform. At the Triceratops chase, allow the SECOND Pterodactyl to capture you. (Make sure you don't have an Aku Aku mask) You will then be dragged away to level 32 (Eggipus Rex).
99 Lives
During gameplay, press L1, R1, X, Circle, Circle, Triangle, Square, R1, L1.

Instant Uka Uka
Press Triangle + Circle + X + Square. Note: This may only be done once per life.

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 Crash Team Racing

Penta Penguin
At the Main Menu, hold L1 + R1 and press Down, Right, Triangle, Down, Left, Triangle, Up. If done correctly, you will hear a sound.
Race as Ripper Roo
At the Title screen, hold L1 + R1 and press Right, Circle, Circle, Down, Up, Down, Right.
Race as N. Tropy
At the Title screen, hold L1 + R1 and press Down, Left, Right, Up, Down, Right, Right.
Spyro the Dragon 2 Demo
At the Main or New Game screen, hold L1 + R1 and press Down, Circle, Triangle, Right.
Papu Papu
At the Main Menu, hold L1 + R1 and press Left, Triangle, Right, Down, Right, Circle, Left, Left, Down.
Komodo Joe
At the Main Menu, hold L1 + R1 and press Down, Circle, Left, Left, Triangle, Right, Down.
Pinstripe
At the Main Menu, hold L1 + R1 and press Left, Right, Triangle, Down, Right, Down.
Super Turbo Pads
At the Main Menu, hold L1 + R1 and press Triangle, Right, Right, Circle, Left.
View Turbo Counter
At the Main Menu, hold L1 + R1 and press Triangle, Down, Down, Circle, Up.
Always Invisible
At the Title screen, hold L1 + R1 and press Down, Left, Right, Up, Down, Right.
Get Scrapbook
At the Title screen, hold L1 + R1 and press Up, Up, Down, Down, Right, Right, Left, Right, Triangle, Right.
Infinite Aku-Aku/Uka-Uka
At the Title screen, hold L1 + R1 and press Left, Triangle, Right, Left, Circle, Right, Down, Down.
Infinite Wumpa Fruits
At the Title screen, hold L1 + R1 and press Down, Right, Right, Down, Down.
3 Battle Arenas and Turbo Arena
At the Title screen, hold L1 + R1 and press Right, Right, Left, Triangle, Right, Down, Down.
Infinite Bowling Bombs
At the Title screen, hold L1 + R1 and press Triangle, Right, Down, Right, Up, Triangle, Left.

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 Crime Crackers

Animation
At the title screen, press Up, Up, Down, Down, Left, Left, Right, Right, and Select. The "Start" option will change to "Animation".