Currently on Steam there's a Spring Cleaning Event where players can earn badges completing various tasks. Perhaps more interesting is that fact a grand total of nine rather great titles will be free on Steam over the weekend (a long one in the UK and US). The following titles can be enjoyed now and until May 28 at no charge:
Borderlands 2
Castle Crashers
Cities Skylines
Dead by Daylight
Dirt 4
Don't Starve Together: A New Reign
Left 4 Dead 2
Middle-earth: Shadow of Mordor
Tyranny