Use the following codes to enable the corresponding function:
God mode: up, down, up, down, left, right, left, right
Infinite ammo: right, left, right, right, left, right, left, left
Add million bucks: right, down, left, up, up, left, down, right
Get all shop items: down, down, down, down, up, left, right, right
Reset all faction moods: up, up, up, up, down, down, right, left