
In the game's opening, Bowser and his Koopalings once again attempt to kidnap Peach. However, this iteration has a large moat surrounding the castle (as in Super Mario 64 and other games), an extra story, as well as two extra towers on either side of the central tower. It seems to be in the same place as it was in New Super Mario Bros. U, New Super Luigi U, and New Super Mario Bros. New Super Mario Bros.Peach's Castle is the final area of the main game in New Super Mario Bros. The castle bosses ( Monty Tank and Roy Koopa) make use of Bullet Bills in their battles.However, Rock-Candy Mines can also be unlocked by the jungle-themed world and upon completing Rock-Candy Mines unlocks Meringue Clouds, the seventh world taking place in the sky, whereas World could not be unlocked by World 4 and skips World 7 upon completing the Castle. Additionally, both worlds can be unlocked by either the beach-themed or snow-themed worlds.Both worlds are the sixth worlds that Mario and company will tackle, in canyons high up in the sky, and both feature two Towers, without a Ghost House.World 6 also shares a lot of similarities to Rock-Candy Mines from New Super Mario Bros.And, upon completing the Castles, Mario or Luigi skip an optional world, (World 3 skips World 4, and World 6 skips World 7), jump straight onto another world above (World 5 and World 8 respectively).Both worlds have a non-scrolling underwater level ( World 3-3 and World 6-5), before another level that introduces new enemies ( World 3-, which introduces Boo]s and Splunkins, and World 6-6, which introduces Chain Chomps) before going to the Castle, if taking the main path.For the first Tower and the Castle in World 6, said enemies and obstacles are swapped around. In a strange parallel, the Tower and Castle in World 3 prominently featured Koopa Troopas, and Skewers with Dry Bones respectively.Additionally, there are two main levels and the unlockable level before the Tower. On both overworlds, the player can choose to start with either the first levels or an unlockable level.

World 6 can be considered to be the mountain-themed counterpart to World 3.
