Thanks! The mechanics for flattening the view wasn't that difficult. You just need to change the projection on the camera to orthographic and then extend the size of the colliders on the platforms and pick up objects in the direction the camera is facing. To determine the player position when switching back to 3D you can use a RayCast from just below the camera position to see which object the player should be standing on. I was pleasantly surprised when I tried it and it worked first time.