1. Total War: THREE KINGDOMS
The latest in the Total War series from Creative Assembly was just released this week with Linux support on day one. Certainly a great release for those into grand strategy games. Three Kingdoms takes the Total War formula to ancient China in this iteration.
2. Neverwinter Nights Enhanced Edition
Beamdog studios has made a name for itself updating and rereleasing old PC RPGs. Neverwinter Nights enhanced edition had a rough start but Beamdog have continued to update it and things are in a great place right now. The base game and DLC on a steep discount this weekend. I highly recommend playing through the Darkness Over Daggerford premium module. It's incredibly well made and there's no prior Neverwinter experience needed.
3. Regions of Ruin
The base-building RPG hybrid Regions of Ruin was just recently added to GOG and it's on sale to celebrate. You'll be able to pick it up for 90% of it's release price.
4. Cities: Skylines
It seems like every month Cities: Skylines is on sale. This time it's to promote the new Campus DLC which enables you to build universities, and everything that goes along with them, in your city. But it's definitely worth taking advantage of the sale and picking up the base game for some city-building fun.