1. Hold the X button down, the following menu will come up
Press the start button
You are now a placeable ring
Controls are as follows:
L and R move up and down
Start + B to place
Start + A to latch on to the nearest item and pick it up
A+D-Pad to cycle through items
D-Pad to move direction
Start+L to zoom out
Start+R to zoom in
Start+X to move cursor to the immediate ground below
Start+Left stick to change camera angle
A+B will set Action Mode
available actions are Place, for placement, Multi, which Im not sure of, and System, which toggles the data type between "Common Set" and "Player Dependent Set"
While in system, you can exit debug mode by pressing A+X
If you're Sonic, you'll enter a mode where you can move sonic anywhere on the map. Commands are:
Left stick, to move Sonic across the X and Z planes
X+Left stick, to move sonic across the Y axis