ARMA: Cold War Assault is free to own forever via Steam. As long as you claim a copy before the 3rd July at about 6pm UTC+1.
This game was also recently given free on GOG.
The horrors of WWIII are imminent. There are clashes over the Malden Islands from dusk to dawn and you are caught in-between. You must use all of the available resources in your arsenal to hold back the incoming darkness. Victor Troska came back to Nogovo, he thought the pain of war was left buried in his past.
But his dream lies broken now.
His worst nightmare returns when military forces lands near Nogovo.