1. At the main menu press Circle, Left, Right, Circle, Up, R2. A "Cheat" menu should be on the options screen allowing God mode, all weapons, and unlimited ammunition, unlimited oxygen, no chestbursting, and level selection.

RESEARCH MODE:
At the main menu press Square, Up, Down, Circle, Left, R1 at the main menu. A "Research Mode" selection wil appear on the options screen