THE BIG CHEAT:

To unlock every code at the code screen in an easy game enter in:
bewareoblivionisathand.

Big Hands and Feet Mode:

To give the creatures in T2 big hands and feet, simply enter the following
at the cheat entry screen and activate it in the Cheat Menu:
STOMPEM 

Big Head Mode:

Go to the "enter cheat" menu and enter the following code. Then start a new
game and push start to access the cheat menu.

UBERNOODLE -- Big Head Mode. Will make all the enemies' heads a lot bigger. 

Gouraud Mode:

Enter the following code at the code entry screen and all textures will be
replaced by simple colored gouraud-shading:
WHATSATEXTUREMAP 

Pen-and-Ink Mode:

To get the good old pen-and-ink mode from Turok 1, enter the following at
the cheat entry screen:
IGOTABFA

Shoot the Birds:

Before you say "duh, I knew that!" -- did you know that there is a purpose
to killing the seagulls in Level 1? If the one gate that's not opening on
top of the ladder near the city bugs you, shoot down all the birds and it
will open. 

Stick Men Mode:

To get every enemy to be tall and skinny, enter HOLASTICKBOY at the Cheat
Menu. 

Tiny Enemy Code:

Want to have every creature be the size of a Compy? No problem, simply
enter:
PIPSQUEAK at the code entry screen. 

Unlock Cheats:

Everytime you finish a level in Turok 2, one cheat in the game's Cheat Menu
will become unlocked. To switch the cheats on or off, simply go into the
Cheat Menu. Here are some of the level codes:

Level 1: Frooty Stripes
Level 2: Pen and Ink Mode
Level 3: Gouraud Mode