World 6 (Super Mario World 2: Yoshi's Island)

"You can, ah, will, aaah, never enter the Koopa Kingdom! I banish you to forever twinkle in the heavens. BEGONE!!"

- Kamek

World 6 (also known as the Koopa Kingdom) is the sixth and final world of Super Mario World 2: Yoshi's Island and its re-release Yoshi's Island: Super Mario Advance 3, resembling the landscape and environment of Yoshi's Island. The world contains eight normal levels. Its mini-boss is Tap-Tap the Red Nose; the main and final boss is Baby Bowser. This world includes many dangerous obstacles, including lava and spikes, the world's theme is a barren landscape in sunset/starry night sky. Its extra level is Extra 6: Ultimate Castle Challenge, its secret level is Secret 6: Endless World of Yoshis, and its Bonus Challenge is Bonus 6: Slot Machine.

List of levels

 * 6-1: Scary Skeleton Goonies!
 * 6-2: The Cave Of The Bandits
 * 6-3: Beware The Spinning Logs
 * 6-4: Tap-Tap The Red Nose's Fort
 * 6-5: The Very Loooooong Cave
 * 6-6: The Deep, Underground Maze
 * 6-7: KEEP MOVING!!!!
 * 6-8: King Bowser's Castle
 * Secret 6: Endless World of Yoshis (Super Mario Advance 3: Yoshi's Island only; known as "Crazy Maze Days''' in British English)
 * Extra 6: Ultimate Castle Challenge (known as "Castles - Masterpiece Set" in Super Mario World 2: Yoshi's Island)

Profile
Super Mario World 2: Yoshi's Island Nintendo Player's Guide description: ''The bones of foolhardy souls litter the final approach to King Bowser's Castle, but Yoshi and Mario aren't about to give up the ghost. Bowser and that mean Magikoopa, Kamek, deploy all demons in an effort to stop our heroes. If the Skeleton Goonies don't put a chill down your spine, the lava lakes will make things frightfully hot for you. Do you have the spirit to scare off these final fiends and reunite Mario with his twin brother?''