Hyperspeed Slide Kicking
Hyperspeed Slide Kicking (HSSK) is a technique where Mario can build up speed by slide-kicking repeatedly against a wall.
Setup
Mario must be placed facing perpendicular to an unreferenced wall, and next to another wall (that is allowing the wall in front of Mario to be unreferenced). He must also be standing on a slide surface with low enough slope that Mario doesn't start sliding.
Constraints
The wall Mario HSSKs against can't be against an OOB wall-- otherwise he'll bonk.
The max speed Mario can attain is 400 before he clips through the wall.