Fear Effect 2: Retro Helix

Infinite health 
Choose the "Credits" selection from the options screen. Then, press L1, Triangle, Up, Down, Circle, Circle, Triangle, Square, Right, Square. 
Expert mode 
Choose the "Credits" selection from the options screen. Then, press Down, Down, Down, Triangle, Down, Down, Down, Square, Left, Right for tougher enemies. 

Rapid fire 
Choose the "Credits" selection from the options screen. Then, press L1, Triangle, Up, Down, Circle, Circle, Up, Up, Up, Down. 

All weapons 
Choose the "Credits" selection from the options screen. Then, press L1, Triangle, Up, Down, Circle, Circle, Triangle, Square, Up, Circle. 

Maximum ammunition 
Choose the "Credits" selection from the options screen. Then, press L1, Triangle, Up, Down, Circle, Circle, Triangle, Square, Left, Triangle. 

Instant puzzle solution 
Choose the "Credits" selection from the options screen. Then, press L1, Triangle, Up, Down, Circle, Circle, Down, Down, Down, Up. 

Instant death with all firearms 
Choose the "Credits" selection from the options screen. Then, press L1, Triangle, Up, Down, Circle, Circle, Triangle, Square, Down, R1. 

Instant death with all Melee weapons 
Choose the "Credits" selection from the options screen. Then, press L