Seattle-based developer Zombie Studios, the team behind Blacklight: Retribution and creators of the Spec Ops series, announced today that it has closed its doors after more than 20 years of game development.

The owners of Zombie Studios say they're retiring and handing off remaining work, including ongoing development and ownership of Blacklight: Retribution, to new studio Builder Box Games. The new studio is comprised of ex-Zombie employees and is lead by the former director of production and the former technical director of Zombie Studios, Andy Kipling and Russell Nelson.

"What does this mean for you the fan? While ownership of the game has changed, the people behind the scenes who have been constantly contributing to the Blacklight universe for the last four years remains intact," Kipling and Nelson, co-CEOs of Builder Box, wrote on their Facebook page. "Builder Box will be working with Perfect World so that, as a fan, you can look forward to more updates and exciting changes in the coming year.

"Thank you for all the support that you have given Zombie and Blacklight over the years, and we look forward to your ongoing support as we transition to Builder Box."

In a goodbye letter posted to the Zombie Studios website, the studio thanked its fans and employees for their support, dedication and passion.

Zombie Studios was founded in 1994 by Mark Long and Joanna Alexander, who both served as CEO of the independent developer. Long left the company in 2011 to join Hawken studio Meteor Entertainment. Zombie developed more than 30 titles, including Blacklight: Tango Down, the Saw games for Konami and a number of Spec Ops games and expansions. The studio released Blacklight: Retribution through Perfect World Entertainment in 2012 for PC, and later brought the game to PlayStation 4. Zombie released horror game Daylight last year.