On August 16, 2010, Microsoft announced "Age of Empires Online", which was a free-to-play Games for Windows Live online game, it developed in collaboration with Robot Entertainment. It featured Free-to-play experiences via Games for Windows LIVE as well as: A persistent online capital city that lives and grows even when you're offline, Cooperative multiplayer quests, trading and a level-based system that lets you progress at your own pace. Premium content could be earned or purchased, such as access to blueprints and special items, as well as more quests and features. In September 2013, it was announced that the game would remain functional until July 1, 2014, after which it would be shut down due to the content being too expensive to maintain.