For the city building simulation Cities Skylines the 3-year-anniversary-patch with free "Surviving Mars"-assets has been released on Steam for Linux.
It contains a new unique Rocket City building called Xchirp Launcher, an astronaut Chirper, and a new free radio station "Official Mars Radio":
The huge Update 1.4 called "Away with Words MK-II" for Kerbal Space Program adds new localizations and an Update to Unity-Engine 2017.1.3p1 among other things to the game.
The update is currently only available for the Steam-version, but other resellers like GOG will follow soon.
For Rocket League a new (paid) DLC has been released on Steam: the DC Super Heroes DLC Pack.
It contains two Bat-cars and more than 20 customization items from the DC-Universe:
Experience the ultimate DC Comics crossover as two classic Bat(tle)-Cars from 2012’s The Dark Knight Rises and 1989’s Batman come to Rocket League!