SpongeBob SquarePants: The Cosmic Shake

This Achievement takes place at the end of the Karate Downtown Bikini Bottom level, after making your way to the top of the skyscrapers.

The checkpoint is called Karate Sandy.

If it's your first playthrough I would recommend making a save before starting the fight or if you've already finished the game you can chapter select directly to the level and checkpoint.

Here's my quick step by step guide.

Avoid taking damage while fighting Sandy or you'll have to load last save or come back to this to try again. Achievement/trophy pops if you're flawless.