To traverse this level, you must ride the icy lifts contained in each half of the Tower. As one of these lifts moves through an area, it picks up some unwanted passengers. Stomp the Bone Goombas as they appear, and use Buzzy Beetle shells to defeat any Bone Piranha Plants that make it onto the lifts.
The first Star Coin is located between the Bone Piranha Plants at Point 2. As you approach the enemies, position yourself directly under the Star Coin and jump up to collect it.
The second Star Coin is located through the small pipe at Point 3. Only Mini Mario can enter this pipe—to collect this Star Coin, you must bring a Mini Mushroom into the level.
After you pass through the pipe, make a running leap up to the Star Coin.
The second lift takes you past two ! Pipes. The first ! Pipe contains three 1-Up Mushrooms, but the ! Pipe at Point 4 contains a Super Star. The lift is about to pick up several enemies, so try to grab this power-up before it’s too late!
The blue pipe at Point 5 leads to the level’s secret exit. Enter the pipe and follow the path out of the Tower. Reach the Goal Pole to unlock the path to World 4-C.
The third Star Coin is located at Point 6. Use the nearby platforms to reach the Star Coin before the lift carries troublesome enemies into the area.
The final chamber contains two wheels, each of which holds two Reznors. After you enter the room, jump on one of the vacant ? Blocks. Deal with the Reznors on the first wheel, then jump across to the second wheel and repeat the process.