Acorn Plains

Acorn Plains is the grassy first world of New Super Mario Bros. U and New Super Luigi U. It lies south of Layer Cake Desert, west to Sparkling Waters, Soda Jungle and Rock-Candy Mines, and south-west of Frosted Glacier, Meringue Clouds and Peach's Castle. It is a plains world with acorn trees, blue-green hills, shrubs, jagged mountains reminiscent of some of the backgrounds in Super Mario World and the world's most defining feature, the Acorn Tree. This special tree is one of main sources of the game's new power-up, the Super Acorn. It can be found in the game's intro, Acorn Plains' map section and said world's first level. This world has eight levels, with 5 normal levels, a secret level, a Tower, a Castle, a red and green Toad House, a Piranha Plant Enemy Course, and a spot where a magenta Baby Yoshi walks near. The Castle boss of this world is Lemmy Koopa.

Challenge Mode Original Courses

 * Acorn Plains Speed Run - Time Attack
 * Castle Coin Bypass - Coin Collection
 * Full Speed Ahead - Time Attack (Original Course)
 * Graceful Glide - Special (Original Course)
 * Hot-Air Yoshi Ride - Coin Collection (Original Course)
 * Paratroopa Panic - 1-Up Rally (Original Course)
 * Star Connection - 1-Up Rally (Original Course)
 * Stingy Big Piranha Plants - Coin Collection
 * The Goombrat Stomp - 1-Up Rally
 * Time Attack Trial - Time Attack (Original Course)
 * Triple Jump for Coins - Coin Collection (Original Course)
 * Waddlewing Wipeout - Coin Collection

Boost Rush Courses

 * Acorn Plains Way – Easy Pack
 * Mushroom Heights – Acrobat Pack
 * Lemmy's Swingback Castle – Flying Squirrel Pack
 * Yoshi Hill – Yoshi Pack

New Super Mario Bros. U

 * Goombas
 * Koopa Troopas
 * Waddlewings
 * Piranha Plants
 * Buzzy Beetles
 * Dry Bones
 * Monty Moles
 * Venus Fire Traps
 * Super Piranha Plants
 * Goombrats
 * Hammer Bros.
 * Podoboos
 * Bloopers
 * Blooper Nannies
 * Blooper Babies
 * Boss: Boom Boom
 * Boss: Lemmy Koopa

New Super Luigi U

 * Koopa Troopas
 * Waddlewings
 * Piranha Plants
 * Dry Bones
 * Monty Moles
 * Hammer Bros.
 * Super Piranha Plants
 * Rocket Engines
 * Munchers
 * Cheep Chomps
 * Cheep Cheeps
 * Deep Cheeps
 * Big Deep Cheeps
 * Eep Cheeps
 * Big Eep Cheeps
 * Boss: Boom Boom
 * Boss: Lemmy Koopa

Mario Golf: World Tour
Acorn Plains briefly appears in Mario Golf: World Tour as part of Nabbit's victory animation. He traverses through a modified version of Acorn Plains Way, until he reaches the top to jump high in the sky.

Super Smash Bros. for Wii U
Acorn Plains appears in Super Smash Bros. for Wii U as a part of the transforming stage Mushroom Kingdom U, presumably as the starting area. The Acorn Plains section of this stage features grassy platforms of different heights. Occasionally, Stretch Blocks and giant icicles will appear.