As the English for medium and hard stages, just start with a wall boxing in your blockhouse and line it with redcoats. After that, begin transitioning into a 2 thick wall of green-jackets and after that you should pretty much be fine, so long as you remember to fix your walls, and if they are hit, upgrade them.
Remember my training... What exactly was it that I was trained to do? Why oh why is there a chicken in a man suit? Great game, just want these questions answered. :P
It's a nice twist on war, but I would have to agree that only having AI is a bit limited. Lots of potential, and if there was a re-release or patch that made it multiplayer, I could see it being amongst the highest rated games. ^ ^