Awesome game! I do wish the map was a little bigger. I felt like the only viable option was to kite around the small body of water near the center of the map. Additionally, I accidentally took the center upgrade several times (more times than not, actually) because I was trying to click to shoot an arrow. Some sort of timer (even .5-1 second) before the upgrade buttons become active would be excellent.
Again, a super fun game! Great job!