This mansion will be your first encounter with Boos and Big Boos. Early on you can pick up a Fire Flower. Keep it on standby to switch between it and a Cat Power-Up. The fireballs can momentarily cause a Boo to disappear. This area also gives you a choice to take stairs downward, or upward. The lower path is a dead end, though.
The lower path dead end contains a moving floor that slows your escape by quite a bit, and it’s guarded by a Boo. You’ll see more moving floors throughout this mansion.
Green Star #1
On the upper path, you pass a large painting of a Boo. Jump into this painting to reach a secret room where you can get the first Green Star. The room is protected by a row of Peepas, and you’ll have to avoid them while the room rotates around until you can eventually reach the star. You’ve got 10 game seconds before you’re booted out, so you can’t afford to miss your first opportunity.
Stamp
Not far from the painting, there’s a couch on the side of the corridor. Stand on it, and it will float up, taking you to the Stamp.
Green Star #2
The second section of the mansion places you in a library guarded by a pair of Boos. If you stand on some of the shelves, they either extend outward, or retract into the wall. You want to try to stand on the shelves on the left side of the room, for when they retract, they reveal the second Green Star.
Beyond the Checkpoint Flag, you come across a Big Boo guarding a large moving stairway leading to the next section. If you run toward the camera in front of that stairway, you can find a hidden set of cloud platforms leading to a 1-Up.
This pipe is actually an illusion! Expect to see this trick happen often in later ghost houses. Be careful about making the jump to the next door—part of the floor collapses into the abyss, forcing you to make a longer jump to survive.
You’ll have a brief excursion on the roof of the mansion. The 1-Up here is also an illusion! Just work your way past the Peepas and get to the next door.
This last corridor is the start of the home stretch. Stay on the lookout for Boos as you move!
Green Star #3
At the end of the corridor, next to the door leading to the Goal Pole, is another floating couch. Use it to ride to the ledge above the exit, where you’ll find a fake pipe. Once you jump on it, it will disappear and reveal the last Green Star.
The final run to the Goal Pole is hectic. Big Boos and Peepas work together with moving floors to try to stop you, and worse still, the first Goal Pole you see is a fake! Keep running past it and make your way to the real Goal Pole!