Soda Jungle

Soda Jungle is the jungle world in New Super Mario Bros. U and can be the fifth area in the game if the player chooses the other way. It can be reached by completing Wendy’s Shifting Castle and going south, or by completing Larry's Luminant Castle and going north. This world, as the name implies, takes place in a jungle that's inspired by Big Island from Super Mario Bros. 3, Forest of Illusion from Super Mario World and World 5 from New Super Mario Bros. Wii in terms of appearance, layout and theme as the jungle is giant-themed within both the world map and the normal levels, which there are 5 of in this world, as well as giant versions of enemies, like Grand Goombas and Gargantua Koopa Troopas. The dead trees in the center of the jungle leads to a haunted area, containing a few extra courses, including Boo enemy courses. When the player enters the area, the area pixelates before loading again. The name is derived from soda and is a reference to Soda Lake. There are eight levels in this world, with five normal levels, a Ghost House, the Fortress level and Castle level.

The boss of this world is Iggy Koopa, who is the boss of both the fifth world in the game (like he was the boss of World 5 in the Wii predecessor) and the boss of a big-themed world (much like how he was the boss of Big Island).

Inside Soda Jungle

 * Soda Jungle-1: Jungle of the Giants: This level features Mega Goombas, Gargantua Koopa Troopas, giant blocks and giant pipes.
 * Soda Jungle-2: Bridge Over Poisoned Water: The second level of Soda Jungle.
 * Soda Jungle-3: Bramble Jungle: The third level of Soda Jungle.
 * : Snake Block Tower: The Tower level of Soda Jungle.

Haunted Area

 * : Which-Way Labyrinth: A Ghost House.
 * Soda Jungle-4: Painted Swampland: A haunted level with Vincent van Gogh's The Starry Night painting as reference for the background, Toxic Water and Circling Boo Buddies.
 * Soda Jungle-5: Deepsea Ruins: The fifth level of Soda Jungle with Moai Heads in Toxic Water.

Outside Soda Jungle

 * Soda Jungle-6: Seesaw Bridge: The sixth level of Soda Jungle.
 * Soda Jungle-7: Wiggler Stampede: The seventh level including a large amount of Wigglers.
 * : Iggy’s Volcanic Castle: The Castle level of Soda Jungle with Iggy Koopa as the boss.

Challenge Mode original courses

 * Mole to Goal
 * A challenge where Mario has to avoid groups of Circling Boo Buddies and get to the goal for a certain amount of time.