Interesting secret in world three. When you run up the enormous rock that moves once you land on it, there are 2 of those falling ledges. When you run through these ledges, you end up with a hole with a sign saying: BEWARE GIANT ANGRY PENGUIN. Although, its just a shortcut.
 "Dillo Hills 2"){kind=icon}
 "FPA: World 1 Remix"){kind=icon}
 "Ninja Warz"){kind=icon}