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 to project an advertisement for its new N8 handset that included the game's characters. A June 2011 T-Mobile advertisement filmed in Barcelona, Spain included a real-life mock-up of the game in a city plaza, while Nokia used the game in Kuala Lumpur, Malaysia to promote an attempt to set a world record for the largest number of people playing a single mobile game. Finnair has also used Angry Birds in their advertising, including taping an Airbus A340 airliner with the Angry Birds figures and holding an Angry Birds tournament on board a flight to Singapore. Rovio has also prepared a