Bow hunting is tough. It takes a lot of practice, so I suggest heading to the practice arena in the game before embarking on the levels. This is a turn-based game that will give you one chance to send an arrow through the heart of your opponent, and if you miss, your opponent will be given the opportunity to send an arrow through your chest. Use the mouse to drag the arrow back. Move the mouse to change the angle of the shot. Keep trying until you get a bead on the enemy. Good luck, and keep a mental note of the numbers used in the angles and power.