Super Mario 64 (N64)
Control the ending camera
After you beat the third Bowser ("Bowser in the Sky"), you can control the camera with the Control Stick on the second controller.
Time is on your side
The entrance to Course 14: Tick Tock Clock is a giant clock with moving minute and second hands. You can affect the moving parts inside the level by jumping into the clock at certain times. Jump in when the minute hand is on the 12, and the moving parts stop. On the 3 they slow down, on the 6 they move randomly, and on the 9 they speed up.
Take it slow
Some inclines that cannot be scaled by running or walking can, in fact, be crawled up. Hold Z and move the Control Stick to crawl up the slope. It's slow, but it works.
For Course 11: Wet-Dry World, when you jump into the entrance painting, the height of your jump determines the starting water level inside the course. With a high backflip, the starting water level will actually surpass the highest switch inside the level...
Some hidden 1-Ups move away from you, but the ones you find while climbing trees and poles will follow you. When you're climbing and a 1-Up starts to appear, immediately jump off and keep running! If you have lots of room to run (for instance, outside the castle), you'll be able to see the mushroom floating in mid-air, following Mario. Since Mario is a tad bit faster than the mushroom, you can have it follow Mario for a long time.
Learning to dive
In Course 4, when you're near a baby penguin, do a dive attack (press B while running). The baby penguin will mimic Mario and do a dive of its own.
In Course 4, return the baby penguin to its mother. After mother penguin thanks you, don't take the star. Instead, pick up the baby penguin and walk away. The mother will get mad and start to chase Mario around.
Fountain of youth
Jump into water to completely refill your power meter. Note that this will not work in the snowy Course 10, because the extremely cold water hurts Mario.
Buns of steel
To minimize damage from a high fall, do a butt-stomp (press Z) before you land. If you time it right, you can walk away with no damage.
It's not easy, but if you succeed in punching (press B) a butterfly, it will either turn into a 1-Up Mushroom or a bomb that explodes quickly.
Dizzy up the pole
Whenever you see wooden poles sticking out of the ground, don't pound them! Instead, run tight circles around them and five Yellow Coins will pop out of each.
After 120 Stars
"M" is for...
Note: Since the U.S. version stops at 999 Coins, this trick only works in the Japanese version.
While fighting Bowser in "Bowser in the Dark World," avoid his fire breath and keep picking up the Coins that come from the flames. When you reach a total of 1,000 Coins in the level, an "M" is added in front of your extra life total, and the numbers next to it change to 25. Next, blow up Bowser or die, it doesn't matter. The weird thing is, as long as you have the "M," the number next to it will go down when you'd normally gain a life, and it will go up when you'd normally lose a life. For example, if you threw yourself off of Bowser's platform after getting the "M25," you'll return with M26 lives in reserve (screen shot #3).
Mario can lose the "M" two ways: If you manage to get a lot of 1-Ups to bring the extra life total down to M1, the next 1-Up you get will change the total to 0, and you'll lose the "M." If you manage to die a lot and bring the total up to M128, the next time you lose a life, you'll lose the "M" and the extra life total changes to 100. Also, if you talk to Yoshi, he'll give you 100 lives, but even if you have M128 it will take them all away until you hit 0 (that's when you lose the "M") and then bring you up to 100 "normal" lives in reserve.