Angry Birds Transformers generated characters to assist in a level for a limited time. Coins may be collected either during runs, popping pigs and/or simply by waiting and collecting coins that generate over time from freed areas. Some levels or features can be only unlocked when the player has upgraded enough Transformers to level 15. The game is the fourth game in the franchise to be compatible with Angry Birds' Telepods, a toy line that is also used in other "Angry Birds" games such as: "Angry Birds Star Wars II", "Angry Birds Go", and "Angry Birds Stella". When using Telepods, it can summon
Angry Birds (video game) for any unused birds. Upon completing each level, players receive one, two, or three stars depending on the score received. Players are encouraged to repeat any previously beaten levels in which the full three stars weren't awarded in order to fully master them and earn the full three star rating. In early 2009, Rovio staff began reviewing proposals for potential games. One such proposal came from senior game designer Jaakko Iisalo in the form of a simulated screenshot featuring some angry-looking birds with no visible legs or wings. While the picture gave no clue as to what type of game