Overkill Software is a video game developer founded in 2009 in Stockholm, Sweden by Ulf Andersson, Bo Andersson and Simon Viklund, formerly founders and owners of Grin. In 2012, Swedish game studio Starbreeze Studios bought Overkill. They are the developers of PAYDAY The Heist, PAYDAY 2, the upcoming Sci-fi co-op game, Storm  and Overkill's The Walking Dead, a co-op zombie survival game.