While playing on stage 2. When you are on the bridge. Go to the spot before the Mini-Boss (The tank on the roof of the building) there is a small bush by the water. It will have a light green area on it. Start shooting that spot several times. Three prisoners will come up and each one will give you 1 metal.

In the final mission, after you land on the ground, don't move. At the exact spot, there will be a tree. Shoot up (Up + square) at the tree's leaves several times until a prisoner fall from the tree. But, be careful as there is a rebel soldier throwing grenades at you.

After beating the game a new option will appear called ANOTHER STORY. Click on it to play three bonus games.

At the Options screen press X, Circle, Square, Triangle, Triangle, X, Circle, Square.