Hyperspeed Walking

Hyperspeed Walking (often abbreviated HSWing) is a glitch that allows Mario to build up speed while walking in steep slopes submerged in water. It is useful in many challenges including the A Button Challenge.

Execution

Steep slopes that normally could not be stood on can be stood on when they are submerged in water. If Mario walks uphill or perpendicular to uphill while standing on such a submerged steep slope, then his speed will decrease. There is no lower bound, so Mario can build up unlimited negative speed in this fashion as long as he can remain on the submerged slope.