Yes, this is it. Thank you!
I'm also wandering something else:
I'm planning a special room for a big boss, where we are in a "cylinder" with platforms attached to the walls, and the boss is in the background, attacking the player
I'm not sure if 2D elements are supposed to interact with 3D ones, so I'll put this way:
If I make a simple room with platforms, make a warp object on the wall (like in pacman, But if the scrolling can't follow, then poop.) and the 3D cylinder follow the motion (while making sure the platforms on the objects are the same from the room, making the player forsee the "next" platforms), would it work?