Good game :)! The difficulty curve is perfect, at first I felt it was a bit to random not knowing which strength the ennemy will have but then based on the look I could easly tell which one to send, and the way that you can still send unit after the first group lost was cool and nice! May be having a small preview at the ennemy attack type could be an improvement.
Also I've enjoyed discovering new unit :D. Well done, good take on the theme !
One small thing that I did not get was why some unity where ressurected and some not.