A very interesting mechanic and premises. The bolt loading control is a bit too finicky for me. Unless the bolt isn't oriented properly with the ballista it won't load at all which becomes somewhat annoying when the ballista is tilted (unless this is as intended).
At a certain point, my stage spawned two dragons below tower level which is impossible for the ballista to fire at. Overall, it was a nice experience and I did learn a thing or two about running away from dragons and ballista operations. Nice entry!