Thanks for playing :)
Yeh If I was developing the game further, I'd add another type of game play to break it up a bit and make it less repetative. Maybe for a future project :)
50 was the max arrow speed deliberatly, at that speed, the archer shoots arrows ever 1/2 second unless you have the tired or slow effects. Thats another thing I'd like to work on improving in a future release, to make the max speed 100.