Like Dark Omen in much better optics. I loved it and so i like your game totally. ;-)
Some suggestions:
1. Different levels of difficulty. Its way too easy. I need some real challenge, even i have to try it 10 times.
2.Just a little bit slower could make it more tactical.
3. Different troopformations would be nice in case you can tie it in usefully.
4. The good suggestions from the crowd, except the guy who´s overwhelmed with ambushes. ;-)
Good work, go on! :-)