First things first:
THIS IS A HORRIBLE PORT!
I am sorry, but it is. This is exactly the mobile game, ported to PC without changing anything. It has no resolution options (and only a low/high quality setting, nothing else). It only runs in window mode or in a stretched (!) fullscreen mode. Really, really bad. I have a native resolution of 1920*1200, so why the hell can't I get this exact resolution in the game? Instead I get this ugly, stretched mess. But ok, I can live with it. Tower defense games were never about the graphics, right? The interface is exaxtly what I know from the iphone. They really didn't change a thing. For instance, if you drag a weapon to a free slot in the armory, it becomes zoomed in in your hand/mouse cursor, which makes sense on a mobile device. It looks horrible and ridiculous on a full HD display though. And they added absolutely nothing. No achievments, no trading cards, no nothing. I really have to assume, that the developers only wanted to make a quick buck with this.
Which is really a shame, because the game itself is actually great. It is exactly what i expect from a tower defense game. Looking at all the newer TD games which try to implement more interaction (like running around with a hero), this is rather old-school. And it is exactly how i like my TD games. Searech for optimal spots for your towers. Find the right balance between getting lots of interest each round and not dying. Love it! And the commander is a nice addition to the already great gameplay of its predecessors. It gives you a little bit of additional interaction, but not too much. For me personally the commander is about as much interaction (besides placing and upgrading towers) as I can take. Perfect!
I really like this game, and that's why it gets a thumbs up. I was really struggling though, because this port is basically a punch in the face of all Sentinel fans. I would have expected more. I pay more money for this than on the iphone after all, so I think i can expect more, right? Whatever, the game is still a lot of fun. If you like traditional tower defense games, this might be the game for you.