Wow, there is so much depth to this game! I think the farthest I made it was to Wave 5 because I had like 3 waves of carts spawn at the same time and then got no leylines, brambles, or inkwells. I love the inkblots because they are a more active way to fight the enemies as a player. I loved making my middle row "cow alley" haha. Keep that ink up high baby!
One thing I didn't realize for a little while was what the harpy was doing. The wings were moving for the animation, but it took me a little big to understand that it was hitting the enemies Possibly adding a little wind sound effect? Or maybe a slight musical something since they are singing a song? There is a slight sound ( I'm pretty sure) of the wings rustling. I get not wanting to fatigue your player with a constant noise though.
Regardless, great job! Really fun game.