World 5-Ghost House (New Super Mario Bros.)
World 5-Ghost House is the Ghost House of World 5. It is accessed upon completing World 5-3, and its own completion unlocks World 5-4 (normal exit), and World 5's Warp Cannon and World 8 (secret exit).
This Ghost House has Broozers that can harm Mario, but can also be used to his advantage. To get the first Star Coin, Mario needs to let a Broozer break some blocks under him, so that he can Wall Jump to the coin. Next, Mario needs to run and jump to a door in the corner of a room. He should quickly Wall Jump to get the second Star Coin (the third Star Coin is in the secret exit). Then, the player should keep going up to find a platform that carries Mario up. It will then stop, wiggle around, fall down, and lastly, it will shoot up to the top. When Mario leaves the platform and goes through the door, he will be at the flagpole.
On the floor above the door that leads to the second Star Coin, the player should see three blocks together. Mario should get on top of them and jump on each one, revealing three invisible blocks. Next, Mario should get on those blocks. He should go to the middle block, then he must jump (or duck and jump if he is Super Mario's size), revealing another invisible block that contains a Beanstalk. He must climb it, avoid the Broozer, and go through the door. There is another platform there that the player must ride. At the end of the ride there is a door, and through the door is the red flag. The Secret Exit opens a path to a Warp Cannon that shoots Mario to World 8.