Fridge Brilliance: The entire Dream World is connected, and not just in a metaphorical way. There's a sign at the end of the Carnival level that says "Haunted Grounds", which is the next level. The end of that level takes place outside of a Haunted House, the third level. Wonder why a part of a room is doing outside of Your Worst Nightmare? That's a piece of the Haunted House from earlier. And said stage ends with a few platforms from The Maze of Illusion.