Not bad could be better
It wasn't that bad. However, what was the point of the buildings. I could guess that it improves the effectiveness of your unit, but I can't be sure. All the units were worthless except the archers. Unleash about 30 to 50 archers and any castle falls before the last archer can even fire a shot. It got really repetitive and so I quit around the 18th level. Could be a lot better. Just explaining the buildings would be a vast improvement.
Hope that helps in the dev of future releases.