Once you have 120 stars, shoot yourself to the top of Peach's castle. Now, climb around on it and go onto one of the steeper areas of roof near the back of the castle. Now, try walking off of it along the wall of the tower. You will be walking on nothingness and be somewhat sticking into the building. I assume the programmers didn't spend much time on the castle roof (Yoshi has spelling errors, and there's the glitch after this) but I thought they'd be able to fix stuff like this up... it's like they programmed a ground in but didn't draw in the textures.
Submitted by: WSB