Bug maybe?
I'm not sure what it was, but throughout the entire game I found my crossbow to be locked in the full upright or down position, leaving me completely useless. All the other controls worked just fine, even the side scrolling, but without the crossbow working properly, it's all for not. Otherwise, decent game, but I've seen it before.
And yes, I did check my keyboard connection, my computer, and reloaded the game. I still have the same problem every time.