Level skip (NTSC version):
Pause the game and enter the passport screen. Go to the "Exit To Title" page and press Z, Y, Z, Y, X(3), Start. Lara will make a sound to confirm correct code entry. Press A to skip to the next level.

Weapons (NTSC version):
Press X, Y, X, Y, Z(4), Y, Z, Y, X(3), Start at the inventory screen. Lara will make a sound to confirm correct code entry. Then, enable the "Level skip" code and use it to advance to the end of the game. Then, begin a new game and activate the "Weapons" code, followed by the "Level skip" code again. All weapons in the game will appear in Lara's inventory.

Unlimited ammunition:
Enable the "Level skip" code, then press X + Up.

Hint: Karate pose:
Stand directly in front of the fireplace in the gym, then press A + Up + B. Release B mid-jump and Lara will make a kind of karate pose.