Selecting towers is extremely buggy. Sometimes the ability to select towers goes away completely, and other times the hitbox for the tower moves to a completely random part of the screen. For example, I have mysteriously clicked the "play" button by clicking on the opposite side of the screen trying to select a tower. Very frustrating. Map scrolling sometimes get locked and trying to place a tower means fighting against the map scrolling as you move the tower.
i also dropped my rating from 5 to 1. started off awesome, but that %@#!@ link has killed me so many times, i'm about to chew glass and boil some kittens