Epic Games also included this service in their game engine Unreal Engine. Gamerscore edit Main article: Xbox Live Gamerscore The Gamerscore (G) is an achievements system that measures the number of achievement points accumulated by a user with a Liveprofile. 23 On August 16, 2013, Microsoft announced that the m PC Marketplace was going to be closed on August 22 alongside the Xbox 360 update that retired Microsoft Points in favour of local currency purchases. In this way, the system attempts to make every match as competitive as possible. 36 Full titles were later added in the form of Games on Demand. 47 On October 22, 2010, Microsoft announced a revamp of Games On Demand under the new branding Games for Windows Marketplace. Developed at Microsoft Research Cambridge ( United Kingdom the TrueSkill ranking system is now used in many titles for Games for Windows Live. "Steam Important Batman Arkham Announcement live ". On August 31, 2012, Gotham City Impostors comes free-to-play and drops Games for Windows live in favor of Steamworks. On August 9, 2013, Microsoft announces the removal of one of the most criticized limitations for the live platform, the inability of simultaneously login in Xbox One and Games for Windows live.