the wario apparition...... 

Mario 64 was previously shown in a game event, its name was SpaceWorld, before the game was launched. In that event when Mario 64 was beying played, also Wario appeared but actually to talk about Super Mario Land 2, where he makes part. So Wario head appeared talking those things: "Do you want fun? Wario show you fun!". Even more back in time, Mario head was present in 1990 to talk to visitors. It was Charles Matinet himself. And that time Mario World game was being shown in the event.