Angry Birds (video game) crates and rocks are incorporated into the structures, and power-ups may be used to enhance the birds to attack hard-to-reach pigs. Also in the levels, players can unlock bonus levels by collecting golden eggs. There are several different types of birds used in the game, distinguished by their color and shape. In the earliest levels only the basic red bird is available. As the player advances through the game additional types of birds become available. Some birds are effective against particular materials, and some have special abilities that may be activated by the player while the bird is airborne. For
Angry Birds (video game) was developing new ports of the game, this time for devices outside of the mobile phone market. In January 2011, three of those ports launched. First, Sony announced the release of "Angry Birds" for its PlayStation Portable handheld system in the form of a PlayStation mini game that includes nearly 200 levels from the original game; the version is also playable on the PlayStation 3. Next, Rovio announced the release of a Windows version of the game on January 4, 2011, available for sale exclusively from the Intel AppUp center, which included 195 levels at launch and plans for exclusive