Metal Slug

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.

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.