Unity of Command: Stalingrad Campaign, an operational-level war game that covers the entire 1942/43 Stalingrad Campaign on the Eastern Front, can now be purchased with 66% discount on Steam for Linux.
Users can play both from the Axis and Soviet perspective, and the game strives to recreate the strategies involved in that part of the war.
According to the developers, you take command in this mobile, back-and-forth sort of war where logistics and poor weather are often the decider, and defeat and victory are sometimes just a mile, or a day, apart.
The system requirements were not made public of the Linux platform, but if the other platforms are anything to go by, most modern computers should be able to run it.
The promotion only lasts until 19.00 CET (Central Europe Time). If you are interested in this game, you should check the official Steam for Linux entry.