A challenging, and really good, RTT
Men of War: Vietnam is a strongly single-player focused Men of War game that, as the name implies, is set during the Vietnam war.
There are two campaigns in this game, one following an American unit, and the other following the exploits of two Russian advisory. Both campaigns are about 6h long, and offer a similarly high degree of challenge. Unlike games like Men of War: Assault Squad or the first Men of War, Vietnam focuses on a very small number of units. Positioning of individual soldiers is the name of the game, not large scale tank combat. This might not be for everyone, but for those who like real time tactical games with a small number of soldiers going up against a far superior foe, where every mistake is costly, it's a real treat.
Speaking of challenge, MoW: Vietnam is a hard game. Contemporary reviews complained about not even being able to beat the first level on easy, and while I would not say that the game is "that" hard, it's still not a cakewalk.
What makes it a 4 and not a 5 star game are some minor interface & control issues. Strides were taken in Assault Squad to make the controls feel more natural, without removing any functionality, and going back to earlier MoW games can be a bit of a shock after that. This game does, for an example, use the arrow keys for movement, rather than WASD. It's far from game breaking, but it is a blemish on what otherwise would be an excellent title.