Total War: ATTILA has recently popped up on SteamDB with pointers towards a Linux & SteamOS version finally coming.
As usual for SteamDB though, don't take it as official:
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About the game (Official)
Against a darkening background of famine, disease and war, a new power is rising in the great steppes of the East. With a million horsemen at his back, the ultimate warrior king approaches, and his sights are set on Rome…
The next instalment in the multi award-winning PC series that combines turn-based strategy with real-time tactics, Total War: ATTILA casts players back to 395 AD. A time of apocalyptic turmoil at the very dawn of the Dark Ages.
How far will you go to survive? Will you sweep oppression from the world and carve out a barbarian or Eastern kingdom of your own? Or will you brace against the coming storm as the last remnants of the Roman Empire, in the ultimate survival-strategy challenge?
The Scourge of God is coming. Your world will burn.