|Game(s)||Newer Super Mario Bros. DS|
|Previous world||(7) Cirrus Heavens|
(6) Lunar Realm
(4) Pumpkin Boneyard (secret)
Koopa Country is the seventh and final world in Newer Super Mario Bros. DS, eighth if one is counting Lunar Realm. It is a Bowser-owned land divided into two parts, the first being a dark deserted wasteland and the second being a lava-filled area. It is represented by a volcano over a red sky.
Koopa Country is divided into two distinct parts as with the original World 8 from New Super Mario Bros. The first part prior to Basalt Bay takes place in a barren desert-themed wasteland. Cacti and quicksand are commonly found throughout. After Ironclad Battalion, Koopa Country turns into a traditional lava theme. Dry Bones and Podoboos become commonplace. At the end is Bowser's very own castle.
Koopa Country can be accessed through three ways, by completing Stormeye Stronghold in Cirrus Heavens, completing Thornspire Doomship in Lunar Realm, or using World 4- in Pumpkin Boneyard, unlocked via The House of Doors's secret exit. Completing Bowser's Castle, finding all 96 exits in the game, obtaining all 240 Star Coins, and the purchase of all Star Coin Signs grant access to Special House in Goldleaf Plains, granting no new levels, signaling the end of Newer Super Mario Bros. DS.
|Level number||Level name||Preview||Description|
|8-1||Boomblast Badlands||A desert wasteland filled with Bob-ombs and Bomb Spikes.|
|8-2||Sandstream Tunnel||A sandy cave where Spinies, Fire Snakes, and Chain Chomps will all try to impede the player's progress.|
|8-||Lavalit Tower||A tower lit up by lava below that gradually gets darker as the player progresses through. At the top, Bowser Jr. is fought.|
|8-3||Wicked Gale Vale||A Muncher-filled desert land with strong gusts of wind which push the player towards dangerous Pokeys and Goombas.|
|8-4||Skyglare Dryland||A desert area where the Angry Sun and Mad Moon team up to fight in their only level.|
|8-||Ironclad Battalion||A barrage of tanks akin to Batallion Frontier in Newer Super Mario Bros. Wii. Monty Tank is fought at the end.|
|8-5||Basalt Bay||A lava-filled volcanic field where volcanic debris will fall from the sky.|
|8-6||Bombkey Banks||An autoscrolling level where the player must avoid Bombkeys, which will explode upon contact with fireballs.|
|8-7||Slitherthorn Grotto||A red lava-filled cavern where Snake Blocks and Spiky Snake Blocks will challenge the player alongside Sumo Bros..|
|8-8||Firehoop Inferno||A volcanic wasteland full of Firehoops seeking to hurt the player.|
|8-A||Magmatrack Getaway||The second and last Minecart-centered level, taking place in a lava-clad cavern.|
|8-||Bowser's Castle||The final castle, and level, of Newer Super Mario Bros. DS. It takes place in Bowser's very own castle, where the player must avoid Bowser Statues, floating Amps, and wavy lava. At the end, the player will fight Bowser and Bowser Jr. in order to finally save Princess Peach from their grasp.|