Doughnut Desert is the second world of New Super Mario Bros. Extreme. It is desert themed. The boss is Roy Koopa
The level starts in a grassy field that will continue through the desert.
2-2: Stone-Eye Sands
This level is similar to Layer Cake Desert-1.
2-3: Fire Bro. Caves
A underground level with Fire Bros. and Piranha Plants
2-Fortress: Thwomp Block Tower
A fortress level with Thwomps and Dry Bones. The boss is Boss Thwomp
2-4: Chain Chomp Wasteland
A level with Chain Chomps and Pokeys.
2-5: Yoshi Ruins
A level that has Pokeys, Hammer Bros., and Yoshi
2-6: Fire Snake Pyramid
A dark pyramid level with Glow Baby Yoshis, Fire Snakes, Fire Bros., and Chain Chomps. There's a secret exit to 2-A
2-A: Sandstorm Clouds
A level with a sandstorm, Paratroopas and Stone Spikes
2-Castle: Roy's Hot Geyser Castle
The second castle. The first half will take place inside with lava geysers, and Big Dry Bones. The second half will be outside with Spiked Balls and Bullet Bills. The boss is Roy.
The battle will take place on a stone block floor with 3 layers. Boss Thwomp will try to crush you. Lead him to a layer and make him crush it. Go to the same layer and repeat it twice and Boss Thwomp will plummet to his doom.
The battle will take place on a lava raft. Roy will try to ram you trying to make you fall to the lava. He will also ground pound and ignite purple orbs.