Vexing Doors

Vexing Doors (Japanese: Obake Yashiki wa Nazo Darake! (おばけやしきはなぞだらけ！ The Ghost Mansion is full of Mysteries!, unofficially known as )) is an e-Reader level for Super Mario Advance 4: Super Mario Bros. 3. The level contains five Advance Coins. It was initially released only in Japan, but became available internationally when the game was released on Virtual Console in 2016.

Layout
The level takes place in a Ghost House. The first room is haunted by a Boo and a Big Boo. There are three doors:
 * The first door seen takes Mario to a room with spikes floor. He must ride a Snake Block to reach an Advance Coin and back.
 * The third one leads to a small room with a Boo and a ? Block.
 * The second one takes Mario to more doors.

Entering the second door, Mario finds himself in a room with another Advance Coin and three doors, but only one of them is visible without pressing a P Switch.
 * The one in the far left leads to a room with two doors. Both take Mario to the same room (filled with invisible ? Blocks) but the upper one allows Mario to get an Advance Coin.
 * The second invisible door and the visible one basically take the player to the same room, but the P Switch door takes them to an Advance Coin room first.

The next room has more doors:
 * Entering the one in the left corner, Mario reaches a room before the Big Boo battle, with three doors that take Mario back to the second room. The last one leads to the battle.
 * The one over Coins can be accessed by pressing a P Switch (only accessible by entering the Advance Coin door in the second room). Mario can collect the last Advance Coin and a Control Coin here.

The battle with the Big Boo is similar to the previous one: Mario must toss three Ice Blocks at him, while avoiding two regular Boos. One of regular boos is faster than usual.