Very, very good.
This is one of the few flash games that I come back to and play more than once. There a couple things that could help with the gameplay though.
- A "retreat" button would help a lot. You can have your soldiers charge forward, but they can never go to a trench behind them. This would be a good idea.
- Tanks are way too powerful. All you have to do to win is start out with a tank and let it unleash it's fury on your opponent. While this may appeal to those who like a quick, easy victory, the rest of us might like a little bit of a challenge. And not the enemy's tank simply obliterating trench after trench of your soldiers.
-I think the whole moral thing should be a bit revised. I've had troops on the homestretch, literally inches away from victory, and we lost because of low moral.
Just a few little suggestions. But all in all, awesome game. I love it. You should make more of these.