Today starts Steams first Free Weekend, which features ten games, all free to play from today until the 19th at 1pm, which happens to be this Sunday. The games will be available for purchase, and discounted, until Monday the 20th at 10am.
The list of playable games is as follows: Payday 2, Company of Heroes 2, Awesomenauts, Trine 2, Blade Symphony XCOM: Enemy Unknown, Don't Starve, Grid 2, Killing Floor, and Injustice: Gods Among Us.
Also, avaliable for pre-purchace is Company of Heroes 2: Ardennes Assault, which continues the original story in World War II. Don't miss this offer and more at store.steampowered.com.