very cool
I loved it... I like that you kept it relatively simple too... meaning just a few types of soldiers, a couple kinds of towers and a fence.... Because there are a lot of this typoe of defence games out there that pile on the complexity to the point where I just no longer find them fun. Although I do understand that for many, the added features and straetgy are actually a selling point, I am a huge believer in the keep it simple principle which I think you applied real well here.
Totally solid and engaging flash, extremely well done!