While in the batcave set up a second controller, either by yourself or with a friend. As z0rrofox mentioned you can use a guitar hero controller if you need to (or a joystick or a whatever). You should then complete a level, in either story mode, and the achievement should pop upon completion.
It's easier to do this with a second person because you can only move as long as both people are moving with the screen.
It's easier to do this with a second person because the game is made for teamwork.
The first levels are obviously going to be the easiest.