Refill Health Without Medic Kit:|
You can do it anywhere, just find a bench and turn your back facing it and move backward, until you sit down. And your health will slowly recover.
All Weapons & Energy (PAL):
During play HOLD Triangle + Circle + Square + X and press Right.
Level Select (PAL):
At the new game screen, press L1 + R1 + Select + Start. Go to the map screen and all levels are unlocked