Adding the tiled backgrounds
Now the creative part, you need 3 backgrounds a little bit wider than the sizes of the window (800 x 600):
Background 1 900 X 600
Background 2 1024 X 400
Background 3 1024 X 140
You can download each one of this backgrounds by clicking [HERE], or if you design better than me (or you think they are ugly), you can create your own.
Every background will need a layer:
For Layer 0 we add BG1.png.
As you can see, the background image is wider than the window.
For Layer 1 we add BG2.png.
For Layer 2 we add BG3.png.
This is what we have: