Major Nelson has announced all the free titles coming to the service this month, including Peggle and Costume Quest 2.
Xbox One owners with an active gold membership will be able to download Defense Grid 2 from May 1, and have the entire month to play it.
Costume Quest 2 drops on May 16, which will be available in the online marketplace until June 15.
Related: Upcoming Xbox One Games in 2016
Xbox 360 players can download Grid 2 from May 1, followed by the original Peggle on May 16.
Both of these titles are backwards compatible on Xbox One, making it easier for One owners to bag their free goodies.