Directions:

Unlock everything:
Pause the game, then press Right Trigger, Black, Y, Black, Left Trigger, White.

Infinite health:
Pause the game, then press Black, White, Left Trigger, X, Left Trigger, White.

Render all AI in X-Ray:
Pause the game, then press Left Trigger, Left Trigger, Right Trigger, Left Trigger, Y, X, White, Black, Black, White

Render all AI in Freeze:
Pause the game, then press Right Trigger, Left Trigger, Black, White, Left Trigger, Y, Y, Black, Right Trigger, White.