This game is extremely fun to play at is at an amazing price too ($15). I highly recommend this to those who enjoy building and destroying.
Gosh this game is brilliant! It's not a simple game by any means even though it looks that way maybe on first glance. Expect to have a learning curve of 1 - 2 hours until you can hold your ground in a multiplayer game.
There's a great campaign to guide you along the way which is quite fun to play but the meat of the game to me is in the Multiplayer. You can play up to 4v4 with shared or separate control (as in everyone controls one fort) and that's where the game really starts to shine as you have a couple different approaches to everything and counters to them as well. There's nothing more satisfying than taking down that pesky fort that you have hammered for quite some time now with a surprise attack the enemy didnt see coming. Coordinating your attacks and outplaying your oponents defenses is very very rewarding as you can't turtle forever, at some point you have to bring the fight to your oponents.
Top that off with a simple but great physics engine that limits you in the way you can build. You can slant armor so bullets just ricochet off but now you're giving a prime target for mortars, so what is it going to be commander ?
The game is not perfect yet however, some things especially in the multiplayer lobby need explaining (AI Settings, separate commanders for teammates, more info on maps), more varied Maps for 2v2 / 3v3 / 4v4. But as of now you can expect to have a blast regardless if you're not to serious. (There's no ranked system yet)
There are people who complain about the content, i feel thats not fair as the content comes mainly through what you do with the tools at your disposal, i'm not sure the game needs more weapons as you already have a ton of ways to use them in conjunction to how your build your base etc.
A specific feedback to the devs is also about the machineguns, give us an option to deactivate their automatic fire, but avoid introducing mechanics that one can only figure out when he researches them: that machineguns stop firing above a certain height is unintuitive and not good for whatever reason you implemented it.
Another thing is to take the "E" hotkey into the tutorial, it's the single most important thing in multiplayer as you can use your control groups without looking at them and aiming all over again. People who played the game certainly agree with me there.