Star wars Battlefront? Age of Empires? Halo Wars 2? Brute Force 2 (no way...)?
From IGN:
Xbox Canada community manager Raj Patel has tweeted a mysterious image that contains a hidden message.
Posted below, the image background (click to make it bigger) contains a message written in Morse code. NeoGAF immediately translated the message, which reads:
"Presented by Xbox, 10am PDT, 1pm EST, May 4th 2015"
We entered that phrase into a Morse code translator and the output matched the dots and dashes in the image perfectly.
Source: http://ca.ign.com/articles/2015/01/22/xbox-community-manager-tweets-mysterious-image