Age of Empires II HD, Hidden Path Entertainment's update of the 1999 RTS, has received an expansion pack.
Age of Empires II HD: The Forgotten is now on sale for $9.99 and includes five new civilizations--the Italians, Indians, Slavs, Magyars, and Incas--and four new campaigns, called Alaric, Sforza, Bari, and Dracula.
Two new game modes, Treaty and Capture the Relic, have also been added, as has a spectator mode, and a new "LudaKRIS" map size.
Players can also stream directly to Twitch.tv through the expansion.
Alongside The Forgotten, Age of Empires II HD has been updated to include support for the Steam Workshop and Steam Trading Cards.
Age of Empires 2 HD launched exclusively in April 2013. The expansion and base game are being sold together as a bundle for $29.99.
For more information, check out GameSpot's review of Age of Empires II HD.