What Could Have Been: The Mario vs Mr L fight had multiple games cut from it.The list Super Mario Bros. 2, Super Mario World, Super Mario RPG, Hotel Mario, Super Smash Flash, Marios Fundamentals, along with others not given
Carnation was going to be called Impatience. She was also going to have a crush on Dimentio and have a dog.
There was at least one cut storyline by the name of Breaking The Habit where Void would get addicted to online gaming.
Word of God: Often in the Author Comments there will be little tidbits large chunks of information that couldn't be written into the page that the characters already know, thus avoiding an As You Know.