Instructions
Press the "Square" button while in creation mode to bring up your "Popit," which is a list of items that you can place on your level. Use the left joystick to move through the menu and highlight the "Objects" option, and press the "X" button to enter the objects selection screen.
Use the left joystick to move through the list of materials from which you can build your wall. Each material looks different and has different characteristics. For example, cardboard can be blown up with explosives, but wood cannot. Highlight the material you want to use and press "X" to select it.
Use the joystick to choose a basic shape for your wall. You will select a rectangle or square shape. Highlight the shape you want to use and press the "X" button to select it. The shape will appear on screen, made of the material you have chosen.
Move the wall to the location where you want to place it, with the left stick. Move the right analog stick up, down, left and right to change the shape of the wall. Press the "R1" and "R2" buttons to make the wall go deeper into the level or to make it more shallow. When the wall is ready to be placed, press the "X" button to add it to the level.