I greatly appreciate your feedback! I'll look into fixing the issue with close range targeted. I believe enemies are getting behind the projectile spawn point causing arrows to miss.
What if the camera zoomed out for larger ranges so you could always see the full screen?
Does the enemy speed scale too quickly? It increases with the run time until a cap is reached (2x speed). I think coin upgrade is useful once piercing is unlocked, so enemies that die further away allow you to pickup the reward quicker.