Danger Zone

Danger Zone is the fourth episode of Angry Birds Space featuring 30 extremely challenging — brainteaser-like — levels. The level numbering is "4-1 " through "4-30", implying that Danger Zone is a non-sequential episode. The background of the Danger Zone looks like a space mine field owned by the pigs due to the fact that the mines have Pig Snouts on them. The Danger Zones has planets from Pig Bang, Cold Cuts, and Fry Me to the Moon, as well as the crystal mushrooms from Cold Cuts and Fry Me to the Moon, which still give you 3000 points. In the level selection screen, small mines with no pig snouts can be seen. In addition, one of the small mines can also be presented as a Special Item Bubble when players get 3 stars on all the levels in the Danger Zone.

Rovio's Description
The following is from Rovio's blog post:

"Think you can defeat THE DANGER ZONE? This episode is filled with 30 of the most difficult Angry Birds levels EVER constructed -- we let our level designers go crazy with these ones, and they came up with some brain-wracking levels. Even some of us here at Rovio HQ, where we consider ourselves to be expert pig-poppers, have found ourselves sweating in The Danger Zone!

In other words: this area is for experts only! Think you can master it?

Note: we're working on bringing the Danger Zone to as many platforms as possible in the future, so stay tuned!"

For platforms using in-app purchases, the first level of Danger Zone is available as a free trial. PC users can access Danger Zone after passing all 30 levels of Pig Bang.

Storyline
The following is from The World of Angry Birds Official Guide, as told by the Mighty Eagle:

"Finally the pigs were running scared. With only one eggsteroid left they decide to take desperate measures and mine their evil hoggy empire. It's the Space Flock's most dangerous mission yet. Can they avoid the spiky explosives and grab Ice Bird's precious eggsteroids? Full speed ahead!"

The book also provides an epilogue to the game:

MISSION ACCOMPLISHED? With all the eggsteroids back under Ice Bird's protection, the Space Flock zoom back to Earth. Super Red knows that they should never take things for granted, however. No matter how many times you try to stop the pigs, in no matter what galaxy, the rotten swine always come back for more...

Levels
According to Rovio's discription, this episode is very hard. There are many hard levels in this episode.

Eggsteroids
Eggsteroid 7: 4-16

Eggsteroid 8: 4-24

Trivia

 * The ending cut-scene used to has bird sounds when you clear a level. It has Super Red Bird's launch sound instead in later update.
 * The gravitational fields in Danger Zone are red, instead of blue like in other episodes.