If XCOM 2 having a free weekend isn't your thing or the Tacoma giveaway on Humble Store then perhaps Cities: Skylines will be for you. From now until March 25th, you can download it completely free and play as much of it as you want.
As a reminder, it recently turned four years old and it's showing no signs of slowing down with multiple thousands on it every day. If you do decide to give it a go, I highly recommend the Clouds & Fog Toggler mod from the Steam Workshop to give you a really clear view.
That's another thing that I love about Cities: Skylines, there's a huge amount of extra content available for it like maps, mods, scenarios and more. The mod selection is incredibly varied too from simple tools to automatically bulldoze abandoned or burned down buildings to adding in entirely new ways to play.
Cities: Skylines is easily the most time I've ever spent in a city builder and I've played a lot of them over the years. It's not just the best on Linux, it's the best normal city builder around right now. My one wish is that they continue to work on performance, as a huge city can really bring it down which affects all platforms.
Find it on Steam, as with XCOM 2's free weekend, Cities: Skylines is also on sale with 75% off as are various DLC so you could look to complete your collection if you already own it.