I remember doing random star patterns in a similar way :D
If I were you I would instead of creating this thin line of place where I get points, I would only place a line where it is counted from, and your point for killing an enemy depends on the distance from the said line. That would increase the likelyhood of the player actually using their turrets.
I get 100*X points for killing an enemy for no reason, I don't really like when there are extra zeros for decoration.