It's missing a few vital components to make this a decent TD game.
First, enemy health bars. Second, a more clear distinction between ground you can build on. There was a clear spot on a corner but I couldn't build on it for game reasons. EDIT: It's especially bad because you can only view buildable land when you have enough souls to spend.
Third, while not necessary, would help: a speed function. Having to wait for enemies to march toward available turrets can be a pain.
Also, for some reason, the Shop page is zoomed in.