Not only is the game available for free this weekend, the base game, the Deluxe Edition, and the first expansion After Dark are all on sale and are 60% off through February 22nd.
This comes a day after they released the second expansion for the game entitled “Snowfall.”
“In Snowfall, the difficulty heats up when the city cools down, thanks to a new in-game temperature reading that will have residents bundling up for warmth when the weather outside is frightful,” the developer said, “Cosmetic weather, including rain and fog, has been added to Cities: Skylines as part of a free update. Players who own Snowfall will get to face new challenges such as ensuring that their city infrastructure can handle seasonal heating demands – and, when the snow starts falling, that the roads can stay clear.”
We currently have a Free to Play Weekend on Steam! Play all weekend and don’t pay a cent! Also 60% off Cities base game and After Dark.
— Cities Skylines (@Cities_PDX) February 18, 2016
A trailer for the second expansion Snowfall can be seen below.