I must say, I greatly enjoyed this. But it had a bit of trouble holding my attention. Though it isn't purely a sim (having a cross between being sim and MMO), it still is one at heart-- and I don't particularly like sims. I don't play games for realism, I play games to ESCAPE reality, because reality sucks.
That said, it is certainly a great game. The controls are relatively smooth, with aiming being a breeze as it's done via mouse (or by turning, if your tank doesn't have a turret), movement is with the usual WASD keys, and it's great fun blasting away at tanks with a tank destroyer.
The balance could be a bit better though. American tanks feel so weak and limited-- there's no tank destroyers for them either. The game is basically all about the Russian and German tanks. A pity you can't play a Wolvering tank hunter, or one of the other American tank hunters. Or heck, even one of the British tanks. They're adding in French tanks, but I really wonder what exactly they plan on doing there what with there being basically no France to produce tanks for much of WWII in the first place.
Still, on the basis of gameplay alone, it's a very enjoyable game. There's no real story, there's no single player, there's just you, fourteen buddies, and a bunch of enemy tanks to shoot at. It's simple and fun, and if you're into tank battles I whole-heartedly recommend it. While I am not myself a huge fan of vehicular combat (preferring to play infantrymen/women), I still greatly enjoyed this game.