"killing floor 2" was developed by tripwire interactive, who began work following the release of their 2011 video game "". the game was announced for microsoft windows and linux by "pc gamer" on may 8, 2014. tripwire president john gibson stated "killing floor 2" is the first time they had been able to develop a game with what he thought was a reasonable team size and budget. the original "killing floor" was developed by ten people in a three-month period; by 2014 the studio had expanded to a team of fifty employees. the game was developed using heavily modified unreal engine 3. the developers considered using unreal engine 4 but decided against it as they didn't want to scrap their current work in progress and because of concerns that the game might not scale down to run on lower-end computers. the team launched the game on steam's early access program to get feedback from players on weapon and perk balance.