Super Mario 64 Glitches

Entering Wet/Dry World Through Stairs
First, make sure you DO NOT have at least 70 stars, or the cheat will not work.

On the 3rd floor of the castle, (the floor with the clock) proceed to the star door leading to the final showdown with Bowser. A message will appear saying you need at least 70 stars, or else you will just walk on the eternal staircase. Ignore the message and go through anyway. Proceed to the middle of the stairs. Long Jump backwards up the stairs (first do a long jump, but hold Z and the Control Stick down). As soon as you land, press A again. Do so very quickly, and Mario will fly up the stairs. If you get lucky, Mario will go through the stairs and into Wet/Dry World.