What is it?

The AHC Challenge is a challenge mainly designed to stipulate the action of letting go of the C button, which is designed mainly to make Mario crouch. There are several other restrictions to increase the quantity of interesting-ness in the challenge.

Stipulations

The other stipulations are:

1: Mario must not touch elevators.

2: Mario must not use the gate clip.

3: Mario must not use OoB movement.