Slime Master
Smash Ace
I don't think not knowing exactly how the menu system works warrants a video, there's almost always some unknowns in exactly how a gimmick works prior to release, notably including Cloud's limit mechanic. Doing some very quick and not particularly thorough research, it looks like mii costumes for some of smash 4's DLC were unknown till release. The stage's mechanics might warrant a video, but I don't know that that's enough evidence to say one is definitely happening.