Mini-Mega Island, or World B, is the second secret world in Newer Super Mario Bros. Wii. it is a grassy island with a "big and small" theme. It is unlocked by completing the secret exit in World 2-9: Pillar Pass. Completing the fortress will unlock a shortcut to World 3-6: Bubble Basin. This world's name is related to Super Mario 64's Tiny-Huge Island
The first level appears to have the World 5 background from New Super Mario Bros Wii, but the other levels appear to have the background from World 1 in New Super Mario Bros Wii.
B-1: Mighty Meadow
B-2: Pintsized Plains
B-3: Troopashell Track
B-4: Cheepcheep Creek
B-Tower: Formidable Fortress
- The music in some of this world's levels are remixes of the theme for World 1 from New Super Mario Bros. Wii.
Other buildings in Mini-Mega Island:
- The Minimega Music House is the official Music House for World B. It can be accessed through completing B-2.