Excellent operational campaign game that surpasses Panzer General line of games. The line of Unity games has the feel of east front warfare in WWII: swift breakthroughs with panzers racing to encircle Russian units. It took me several tries to get Decisive Victories in the scenarios, and some scenarios I'm still working my way there.
The game has lots of improvements to gameplay, like extra movement if a unit doesn't attack, showing the route a unit will take to its destination, and being able to undo a move you have just made. Especially nice is the supply line requirement that is simple and easy to observe, without burdening the player with details. This also makes clearing the supply path vital to a successful offensive. And beware, the computer AI will look for an opportunity to cut your supply lines, which can be very embarrassing.
My one minor complaint is that you can't save the campaign game of linked scenarios at the end of each scenario, so failing a scenario means you have to start over. I realize this is a design feature, but I'd still prefer being able to save the campaign. The game does do an auto-save as you progress through the campaign so you can pick up wherever you left off last time.
I highly recommend Unity of Command as a truly fine game.