Serious Sam Double D is a side-scrolling shooter developed by Mommy's Best Games and published by Devolver Digital. It was developed as part of the Serious Sam indie-series for Microsoft Windows and released on August 30, 2011. The developer studio, kept on working on the game and on February 20, 2013, the game was released as Serious Sam Double D XXL for Xbox 360 on the Xbox Live Arcade, integrating more weapons, more enemies, and the long-awaited co-op mode. On October 21, 2013, Serious Sam Double D XXL was released as a free patch for the original Serious Sam Double D for Microsoft Windows.