that's a gud time-waster :P
you don't have to listen to ppl like Shadowtrasher who rant over a game because he got wasted at the first 10 seconds of play, actually, your game is quite funny... especially to make my hand and my mouse all twitchy for a month :P
I find this game particularly better than your first one, which had an annoying interface and one of the most annoying chatting face I could see in a game. In Art of War DX, the interface takes alot less space on the screen, allowing the gamer to see and shoot the invaders faster... altough the chatting faces are yet again popping right where they shouldn't be.
Regardless of all that, I would recommend you to add a pause menu or something, because it is not given to everyone to have bionic muscles beneath their hand's skin. Shooting waves and waves over and over can get really exhausting over time...