Long time fan of this game. Got into it via "Critical Mass", a sci fi space shooter with similar but far simpler gameplay mechanics.
Whilst it is a good simulation and solid gameplay wise, it can get samey - there are only so many ways to win battles against what is a very cunning AI.
To answer Fenrif: Tactical squad based shooter, action unfolding in real time after a deployment phase. AFAIK no multiplayer, though that doesnt mean that it doesnt exists. There is no basebuilding, instead you have a persistent commander in one of the WW2 nations, and lead soldiers in missions that are semi random and take place on procedurally generated maps. You are restricted to whatever troops your nation offers (from infantry with rifles, smg's, lmg's and hmg's, specialised snipers, mortar troops or flamethrowers, armoured units and other vehicles, and a range of AT guns) and restricted by a "cost", so you need to choose between cheap, efficient and expendible riflemen, or expensive, heavily armed yet vulnerable tanks. Gameplay is based around aline of sight model, and features line of sight ideas to determine who can shoot who, and who is supressed/in cover.
What makes it a gem is how it feels to play. Its hard. Its unforgiving. You get missions that are impossible to win which you will have to retreat from, knowing when is the right time. Its easy to pick up and learn but very hard to master. The AI is very very clever, and the terrain and your management of troops has clear effects on the progress of battle - its not simply "most guns wins". Each soldier has a name and record, and behaves, well, like a human. They will hide and refuse to move if they are in danger. They will surrender if outflanked. When Pvt. Ivanovich is shot and killed by an unseen enemy, and it is your fault as you ordered his squad to advance over open land towards a forested hill, it feels bad. When you outflank a superiour force and use the elevation to execute a devastating crossfire killing dozens of the enemy, its no fluke and feels good.
You can get a free demo via "Sean O'Connors Windows Games". A lil google fu will take you to his website. Most of the games are duds other than this one and the one I have already mentioned in this post. Full versions cost money.
Bah, Ninjaed.