You'll begin this stage by watching Batman walk across the top of a building and hop down onto a green, slanted roof.
This is a very short and easy stage. The gimmick here is that you're on the slanted roof of a building and you are constantly sliding downwards to the edge where you can fall off and die.
Move to the right and you'll fight one enemy after another (about five groups in all) until you reach the end (walk to the far side).
The fights are: