I really enjoyed the summoning aspect of this. I might have abused it a little bit on the last 2 stages by summoning the guys that shoot and dashing frantically around the map. I did beat all of the stages though. :)
Somehow, I got the boss to jump outside of the hedge while my wraith guy kept shooting at him until he died. I'm sure this was a bug lol
Only suggestion I would give is the boss could use some kind of indicator as to which direction it's dashing, or where its going to jump. Just a little something to communicate to the player so they can react accordingly. Otherwise, great game!