While not all of the games on sale fit directly as a 'city builder', they all at least have you build and manage something. The Humble City Builder Sale is live and there's some great Linux games in it.
Some good picks for Linux gamers:
- Prison Architect - 75% off
- Cities: Skylines - 75% off / Cities: Skylines - Parklife - 50% off / Cities: Skylines - Mass Transit - 50% off
- Railway Empire - 70% off
- Surviving Mars - 66% off / Surviving Mars: Green Planet 33% off
- Northgard - 50% off
- Rise of Industry - 50% off
- Two Point Hospital - 50% off
- Tropico 6 - 35% off
- Bridge Constructor Portal - 30% off
- Project Hospital - 25% off
- Meeple Station - 25% off
There's plenty of others on sale, you can see the full sale here.
Perhaps you will find your next game, to get you through the weekend and into next week. Personally, I'm torn on a favourite out of those, as there's some seriously good games there. Two Point Hospital feels a bit "on point" right now, although the more comical take on diseases should bring a smile to your face.