As part of a Microsoft-issued press release, it has been revealed that the Survival Pack for zombie shooter Left 4 Dead will hit Xbox 360 on April 21. As promised, the content will be available on that date for free from the Live Marketplace.

To recap, the Survival Pack is comprised of an new multiplayer game mode — Survival — plus versus mode engineered maps for Death Toll and Dead Air. The soon to be added game type can be played across all 12 maps, one of which is an all-new environment known as “Lighthouse,” created specifically for Survival.

Valve has not confirmed a release date on the PC side of things yet. Though, given their obvious commitment to the platform, it’s safe to assume that we can expect a release around the same time.

Read more: Left 4 Dead Survival Mode Details Hit, Left 4 Dead Survival Pack, Source SDK Hits This Spring, Valve Confirms Left 4 Dead DLC Will Be Free On PC, Xbox 360, Left 4 Dead 2 Features Two Additional Gameplay Modes, Savenge And Realism, Left 4 Dead Now 50 Percent Off On Steam