Crumbling Cavern is the fourth world of Mario vs. Donkey Kong: Tipping Stars. It introduces Movable Pipes, a pair of green Warp Pipes that can be picked up and repositioned in different areas. Once a Mini toy enters one of these pipes, it will be warped out of the other one in a different area. All other mechanics that debuted in previous worlds make a return in this world, though without as much focus put on them. The only enemy species introduced in Crumbling Cavern, Fire Piranha Plants, are able to spit fireballs that bounce off the opposing surface and return to the sender, repeating the attack. Other enemies found in this world are Cannon Kongs and a single Shy Guy.