Easy Extra Life

Beat a stage with your time ending in the same digit repeated twice as the tens place of your Star total, and you'll be awarded an extra life.

Example:
With 17 stars, beat the stage with your time ending in 11.

Hear SMB remix

If you sit at one of the levels in Special World for about 2 minutes, you'll start to hear a Super Mario Brothers remix!

Item Conversion at the Goal

Try holding an item (shell, trampoline, etc) and cross the Goal line. The item you're carrying will turn into a 1-Up mushroom.

Berry Freeze

Enter a level with Yoshi, Cape Mario, and a Fire Flower in reserve. Position yourself under a berry in a way that you can get the fire flower and get the berry at the same time. If you happen to eat the flower and the berry at the same time, the game will freeze. Several things have been reported while using this glitch. Sometimes when the game freezes, your coin count will rise until you quickly have 99 lives. Press Start and Select to exit the leve. One person's game froze, horizontal lines appeared on the screen, and weird music kept looping over and over again. Then came a buzzing noise, and he was returned to the file select screen, with his file deleted. Thankfully, that's not normal. Even so, this is an interesting glitch to exploit every once in a while.