World 6 is the sixth world that Mario encounters.
World 6 is completely on a sky.There is also a Star warp in this world which leads to Star World.
Roy Koopa resides in this world.
The path first starts at "Night Galaxy Train" which makes a curve down "Chomp Chomp Panic 2". The path now goes straight to "Warning! Lightning!" which splits the path. The left path goes to "Really Big Jump" which goes up towards "Twin Lifts" which splits the path. The upper path goes to "Dedede's Sky Castle". At the right of that is a Star Wap, an access to Star World while the right path goes to "The Future of UFO's". The upper path from "Warning! Lightning!" goes to "The Future of UFO's" which splits the path. The upper path goes to "Yellow Switch Palace" while the other path goes to "Castle # 6" which ends the path.
There are 9 levels, with 2 forts, a star warp, and a Castle.