This is a game building block and all code blocks are commented. This block provides an example of how to create a side scrolling game. Felix is stuck in the center of the stage while the floor scrolls past him. This is effect is created with two identical sprites, each the width of the screen (If you're drawing them in a paint package outside Scratch make sure your image is 480 pixels wide). When the project starts it creates 2 clones of the sprite and then places them side by side at the bottom of the screen. As Felix walks left and right they are scrolled sideways giving the effect of movement.
Left and Right arrows to make it appear that Felix the Cat is running left and right.