World 3-Ghost House (New Super Mario Bros.)

 is the Ghost House of World 3.

Layout
This level is the first Ghost House in the game. The gimmick of the whole level is that there are several ? Switches placed in the different areas of the level. The ? Switches are used to reveal staircases and certain doors. However, when activated, there is a time limit, and, if the time runs out before Mario reaches the area he is supposed to go, he must go back and hit the ? Switch again.

Secret exit
After pressing the third ? Switch to reveal the regular exit door, Mario must instead pass by that door and go back down the large staircase to find a newly-created door. This exit leads to a Warp Cannon leading to World 6.

Star Coins

 * Star Coin 1 - The player has to enter a door next to a ? Switch. They should jump off a Splunkin to get the first Star Coin.
 * Star Coin 2 - After hitting the third ? Switch, Mario must make his way to the top where he will see a set of stairs from the left side. The player must climb these stairs before time runs out to reach this Star Coin.
 * Star Coin 3 - Mario will need to be in his Shell Mario form to obtain the final Star Coin. Before exiting the level, Mario must dash and hit the Brick Block as Shell Mario. He should enter the newly formed hole and collect the Star Coin.