Strange Mario walk

Quickly hold L + R + X + Y + Up when the Princess is freed in the final level.
Mario will walk strangely during the ending credits.



Climb and carry item

Stand next to a vine with an item.
Hold Up and release Y to throw the object into the air, and quickly climb the vine while holding Y.
Mario will automatically catch the item as it falls, and may continue to climb the vine. 



Uphill Yoshi slide

Face toward a slope and press Down and L or R to slide upward.



Reuse P

Use Yoshi in any level with a P. Immediately after stepping on the P, turn around and eat it again. Yoshi will gulp it, you can then spit it out. When it comes out, the P will be full again.