Game is fun to play, the only thing I would add is that it would be beneficial if you can just shoot an arrow instantly when left clicking on the mouse. It will help when there are a lot of enemies in the way.
The idea behind the game was to not let you shoot constantly, we wanted the players to be in position and shoot carefully. You can instantly fire at 30percent charge so you can constantly fire if you prefer that if you wait less than a second for the bar to charge 3/10th of the way.