Shifty Boo Mansion

Shifty Boo Mansion, otherwise known as World 3-3, is the third course of World 3 in Super Mario 3D World and its Nintendo Switch port Super Mario 3D World + Bowser's Fury. It is unlocked via completion of Snowball Park, and completion of either this level or Chain-Link Charge unlocks Pretty Plaza Panic.

Shifty Boo Mansion additionally appears in the background in Super Mario Maker 2, in the Ghost House theme of the Super Mario 3D World style.

Layout
The level starts in a hallway filled with Boos and a Big Boo, followed by some steps which lead to another Boo infested area with a door. The door leads to a bookshelf-filled room which leads to the Checkpoint Flag and another staircase area filled with Boos. A nearby door leads to an outside area with some Peepas and another door, which leads inside once again. Another step-filled area awaits, followed by a door which leads outside. Some Peepas and Big Boos await, followed by a fake Goal Pole. Some nearby steps lead to the real Goal Pole.

Green Stars

 * Green Star 1: Near the beginning, the player must jump into the Mystery Box hidden behind the Boo portrait to enter a rotating room with Peepas and the green star.
 * Green Star 2: In the library, the player has to move around the bookshelves on the very left to unveil the second green star.
 * Green Star 3: Near the end, the player must stand on the couch at the end of the hallway to take them to the third green star, which is hidden inside a fake Warp Pipe.

Stamp

 * Immediately after the first green star, the player has to stand on the couch that levitates to the stamp. The stamp is a Boo.

Luigi sighting
For this Luigi sighting, the player must first collect all six + Clocks, found in the following locations: If the player completes this task and waits at the end until about 15 seconds are left on the timer, faint 8-bit Luigis can be seen rising from the graves in the background and walking right.
 * One + Clock near first Boo painting
 * Three + Clocks at beginning of the bookshelf area
 * One + Clock near the Big Boo after the Checkpoint Flag
 * One big + Clock in the conveyer belt area

Names in other languages
Auf und ab im Gruselhaus