Currently the game doesn't have any shifting between 'planes' but the background story alludes to it. There are the mysterious portals that brought the Diaboli, and Klyros for certain to Yliakum, the 'plane' of the planet was shifted during a monstrous earthquake which opened the cave system to what is known as the stone labyrinths, and the fact that you shift 'planes' upon death until you recieve true death, From Yliakum to the Death realm and back.
So Planeshift has lots of shifting of planes, Just depends on what your defenition of a plane is!
