Amazing!
I loved this game! It took a while for me to really get into it and work out what I was meant to do, but from about level 5-onwards it was great!
The biggest problem with it for me was, unfortunately, lag. Flash can't really handle moving that many things around at once in a game...
To improve the game, one you complete the 8 levels, you should add a "free mode" where you can build up huge/unusual armies for fun then decide how many enemies to fight against.