In Super Mario World, hitting the very top of a Pokey’s head with a thrown object will display an animation of its head falling off, while not actually harming the Pokey itself.
In Super Mario World, it is possible to start a new file with one coin already collected. To do this, you must bring up the file select menu on the title screen on the exact frame Mario touches a coin during the demo gameplay, and start a new file. If done correctly, the coin counter in the upper right corner of the screen will show 1 instead of 0 during the intro cutscene.
It’s not often Breath of the Wild tells you ‘no’, but on this occasion it did. It was also an occasion where I thought ‘you know what, I don’t think I wanted to anyway.’
It is possible to obtain the “Blast Away the Wall” star in Whomp’s Fortress in Super Mario 64 without using the cannon and destroying the wall, merely by jumping into the wall in a precise spot. However, the positioning and angling used for this glitch are very exact, so that it is much easier to get the star the intended way. (Source)
In Super Mario World, if Mario continuously pushes against a wall during the boss battle against Roy as it moves, he will merge with the wall. This results in Roy’s falling attack not being activated. (Footage recorded by me from a SNES emulator.)
In Super Mario World, it’s possible to accidentally lose a life through a glitch by stepping on a falling springboard near a Bullet Bill Blaster. This is easiest to do in the Outrageous level in the Special Zone. (Footage recorded by me in a SNES emulator.)
A glitch in Super Mario Bros. 3 allows Mario to defeat Pile Driver Micro-Goombas (the hopping block enemies) in an unintended way by simply ducking under them as they land (left) or merely standing still if he is Small Mario (right). Note that this will not work if Mario is touching a wall. (Footage recorded by me in a NES emulator.)