Microsoft has announced the Xbox Live Games with Gold titles for December.
On Xbox One, Gold members can download Warhammer: End Times - Vermintide for free next month.
Telltale's Back to the Future: The Game - 30th Anniversary Edition is also available as a free download on Xbox One from 16th December to 15th January.
On Xbox 360, Child of Eden is available as a free download for Xbox Gold members from 1st December to 15th December. Then from 16th December to 31st December (aka New Year's Eve), Arcade title Marlow Briggs and the Mask of the Death is also free to download. As always, both games are available to play on Xbox One via the Backwards Compatibility feature.