It took me a couple of tries to understand the and then finish it, but after it made click it was quite enjoyable.
I love the art style, although a nice background or some moving clouds would have been great too. Especially using physics for arrow was a good choice. It was nice to see how the arrow bounce off of stuff and fly in random directions. Nice little detail I really like.
It was a bit hard to distinguish my troops and the enemies and there were some visual glitches like faces of my troops are not visible anymore if a knight is behind them and the knight started to moonwalk when he left the screen on the left side and did the whole moonwalk until he left the screen on the right side too while at the same time bashing enemies.
I think with some polishing and a bit more gameplay depth this could be really cool.
Great job!