Background not Crushed

How do I make the background as in Darkorbit?
Effect of distance?
This is the game(Darkorbit): http://browser-game.it/wp-content/uploads/2012/06/gameplay-dark-orbit.jpg

In short, there is not a background crushed. It seems to be right there.
By chance, are the transparency of the background image?

Of course I’m talking about 2D.

Thanks in advance.
Excuse me, if I misspelled something.

There are a couple ways you can go about it in a 2d game.

The easiest way is to just create a material with the texture that you want to display and assign it to a plane that is larger than your camera frustum. But, of course, this won’t work in a 3d game.

The preferred method would probably be to use a Skybox. You can import the Skyboxes package to play with some to see if this is the route you want to take. Otherwise, again, in a 2d game, you can just move the background plane with the camera as long as it is totally fixed and in orthographic mode or doesn’t pan too far.