Age: 42
Occupation: Gaming impresario
Previous TIME 100 appearances: 0
Angry Birds has crushed the mobile-gaming market with 40 million active users playing monthly and over 75 million downloads. Now, with the ingenious Peter Vesterbacka leading the charge as head of business development, the maker of this addictive game, Rovio Mobile Ltd., is prepared to take on the whole gaming industry one slingshot bird at a time. The former Hewlett-Packard employee first discovered key members of the Rovio team in 2003 at a mobile-game competition sponsored by Nokia and HP, in which he was a judge. Vesterbacka told the trio of Rovio co-founders, then a group called Relude, to start their own mobile company. In March 2010, he left his job and joined them. It's paying off: Rovio's latest investment round raised $42 million for the offbeat start-up where some senior staff members are given official bird titles like "Mighty Eagle" (Vesterbacka) and "Bird Whisperer" (official company spokesperson Ville Heijari).