On Xbox One, Xbox Live Gold members can download CastleStorm: Definitive Edition ($14.99 ERP) for free during the month of May. Pool Nation FX ($13.99 ERP) is also being offered for an additional month.
On Xbox 360, starting Friday, May 1st, Mafia II ($19.99 ERP) will be free for Xbox Live Gold members through May 15th. Then on May 16th, Xbox Live Gold Members can download F1 2013 ($39.99 ERP) for free through May 31st.
Read more about May Games with Gold titles over at Xbox Wire.
For the month of May, Xbox Live Gold members will receive three new free games on Xbox One and Xbox 360 as part of the Games with Gold program.