I've realized that so many levels try and kill you by either quickly moving a platform up or down, or moving the stage boundary...
3D World, Golden Plains, to and from Bowser's Castle on PM, Rainbow Road, Spirit Tracks (ugh when you get this in All-Star), Lumiose, F-Zero, Arena Ferox, Dreamland, and Find Mii all do this at points and it's a bit too much. You gotta be pretty much on your game the entire time or you'll get caught by these.
Really disappointed in the stages, overall. Hopefully Wii U tames some of them down, which it seems like most of them are more bearable.