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) exclusive content when played on Chrome, such as exclusive levels and the so-called "Chrome Bombs". The version includes offline playability and features 60 FPS gameplay with a selection of graphics settings to accommodate a variety of hardware capabilities. In October 2011, during Nokia World 2011, it was announced that "Angry Birds" would come preloaded in Nokia's Asha series of Series 40 touch handsets, aimed at emerging markets such as India, China and South Africa. In December 2011, Rovio released "Angry Birds HD", "Angry Birds Seasons HD" and "Angry Birds Rio HD" on the BlackBerry PlayBook tablet from Research In Motion.