World 5-Ghost House (New Super Mario Bros. 2)
From the Super Mario Wiki
The level begins near a group of three ? Blocks, with either a Super Mushroom or a Super Leaf in the middle ? Block. A Swoop is found, along with stairs that disappear and reappear. A Boo is found, along with a group of Hidden Coins and a Swoop. A swinging platforms made of Empty Blocks is found, along with another platform with Hidden Coins above it. After another Swoop, a group of swinging platforms and a Boo are found. A Warp Door is then found. This leads to more swinging platforms, with poles leading to platforms found above. A group of coins around a Hidden Block containing a 1-Up Mushroom is in the area reached by the last pole. A Warp Door is at the end of the area.
The Warp Door leads to an area with a group of ? Blocks and Brick Blocks, followed by a Big Boo. Hidden Blocks can be used to reach a group of swinging platforms. A Warp Door is found at the top of the area, and leads the player outside. Two Boos and some poles are found, followed by the Goal Pole.
The path to the secret exit (which leads to World 5-A) starts with a small opening in the ceiling near the end of the first room, before the first door, above the right extent of the second swinging platform. An invisible block containing a Beanstalk is located directly below it. Alternately, Raccoon Mario can fly up through the opening. Through the opening and up a flight of stairs, a door leads to another room with a series of swinging platforms and ropes. At the end of this room is a yellow ? Switch and a Big Boo. When the player hits the switch, four doors appear. The correct door is at the top-right, behind the Big Boo which must be lured out of the way; there is no time limit to reach the door. If White Raccoon Mario tries to access the secret exit, it will show a path to the normal exit.