Unlimited Ammunition
Press X, A, Y(3), A, X, B at the code entry screen.

All Future Weapons
Press A(3), X, B, X, B(2) at the code entry screen.

Invincibility
Press Y, X, B(2), A(2), B, X at the code entry screen.

Unlimited Continues
Press B(3), X, B, A, Y, A at the code entry screen.

50% Less Health In Combat With Tx
Press B(2), X(3), B, A, Y at the code entry screen.

All FMV Sequences
Press B(3), A, X, Y, X, Y at the code entry screen.

Centipede Mini-game
Successfully complete the game to unlock Centipede at the 'Atari Games' menu. If it is not unlocked as soon as you complete the game, restart your Xbox, reload your game, and recheck the 'Atari Games' menu.

Missile Command Mini-game
In the vet's office on level 13, walk into the small office on the far right side. Approach the computer and press A to play Missile Command. Then, successfully complete the level to unlock the game at the 'Atari Games' menu.

Unlock All Game Scenes
Enter B, B, B, X, B, Y, B, B at the code entry screen.

T-X Endoskeleton In Every Fight
Enter X, B, X, A, A, Y, X, X at the code entry screen.

Unlock All Levels
Enter X, Y, Y, X, B, A, A, B at the code entry screen.