Forza Horizon 3 for Xbox One is currently not available.
Free standard delivery. Free returns.
Overview Reviews
[1] Free Games Offer: For paid Gold members only on Xbox One, active Gold membership required to play free games you’ve redeemed. Restrictions Apply. Savings based on retail value of game. Games sold separately. Requirements and available features vary across consoles; Multiplayer between Xbox One and Xbox 360 supported for select titles. Download required. http://www.xbox.com/backcompat.

[2] PC hardware requirements may vary for games on Windows 10.