This island and mountain-themed area can be unlocked by using the red-flag exit in World 3- Ghost House. This level is the first Ghost House in the game. It is the first and only appearance of Bloopers. Most of this tower is spent climbing on fences. Completing it leads directly to the world's castle. This is the third and final secret level in the world. A level high in the sky, it is made entirely out of pipes. This is the second secret level in the world.

It has a red-flag exit which unlocks a different path that leads to World 3-B. This is the second level in the world, and mostly takes place on tilting mushrooms. This level is the first secret level in World 3. Cheep-Chomps appear here for the first time in the series and make their only appearance in this game. The first level in World 3 takes place underwater. World 3 can be skipped if the player gains access to World 4 by defeating Mummipokey, the boss of World 2, in mini form. After the completion of this world, the player instantly gains access to World 5. World 3 has a total of eleven exits, and the boss of the world is the Cheepskipper. This world features a large beach-covered island, with many ocean- and beach-themed levels featuring Cheep-Cheeps, as well as the first Ghost House in the game. World 3 is third main world in the game New Super Mario Bros.

But don't expect to be lounging on the beach - this world is far from paradise!” - Official website “If you don't find the alternate exit in World 2, you'll find yourself in the tropical landscape of World 3.

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