The slide. Sprite ripped by AJ Nitro.
The Slide attack was used by Bad Mr. Frosty in ClayFighter. He slides along the ground, dodging projectiles and Taffy's Taffy Tornado. This attack requires a quarter circle, which means you have to put your thumb on the down direction of the control pad, then quickly slide your thumb to the forward direction or the backwards direction. Then you have to press the button required to make the move work. In this case, you have to press down forward kick (any strength will do) in order to use this attack.
