Instructions
Walk through the door in the first room of the Yold Desert Ruins. This is the first area you will enter when Chapter 1-4: Monster of the Ruins of ̶0;Super Paper Mario̶1; begins.
Walk through the red door in the second room of the ruins. There is a chest with a Life Shroom in the top section of this room.
Press the ̶0;A̶1; button on the controller to switch to the 3D plane.
Hit the two blocks in the 3D plane of the room. These blocks will be knocked back into the 2D plane.
Enter the red door at the end of the third room. You can reach it in the 2D plane with the blocks from the 3D plane. Ignore the other door in this room, which is currently locked, for now.
Open the chest on the platform in the fourth room. This contains the Ruins Key.
Return to the third room.
Open the locked door with the Ruins Key to enter the fifth room.
Enter the door at the top of the fifth room. Ignore the other locked door for now.
Use Thoreau to throw one of the squigs in the sixth room into the blue switch.
Return to the fifth room. You will notice some of the features of the room have changed.
Use Thoreau to pick up the Ruins Key. It is located near the sand pit.
Open the locked door with the Ruins Key to enter the seventh room.
Use Tippi in the seventh room. A hidden platform will appear to allow you to reach the next door in the Yold Desert Ruins.
Enter the door to reach the eighth room.
Enter the 3D plane on the left side of the eighth room. You will see a Ruins Key that seems to be inaccessible.
Climb the hidden stairway in the 3D plane to reach the platform with the Ruins Key.
Open the locked door with the Ruins Key to reach the ninth room.
Enter the 3D plane to find a ladder in the ninth room.
Press the blue switch and red switch. This will cause a large number of enemies to appear and then drop below the door platform.
Go through the door to reach the 10th room. There are four switches in the room.
Enter the 3D plane. Each switch will have a number on it. This is the order the switches need to be pressed.
Press the switches in order to create a staircase. This leads to Fracktail, the boss of Chapter 1-4: Monster of the Ruins.
Defeat Fracktail. Enter the door located at the end of the boss room. You will see Merlumina in the next room. Talk to Merlumina to complete the Yold Desert Ruins. This will give you the Pure Heart for the level and start Chapter 2.