Thanks for the feedback. The build rules are 1. you cant place two towers directly beside each other and 2. you can't build on unstable terrain such as sand or cliff ledges. I had trouble depicting a cliff ledges from a top-down view and tried to copy what the old pokemon games did (but even those weren't fully top-down ). The idea was the 3X3 area around the tower was suppose to show that it cant overlap with another tower
As for the range, its based on the circle radius, not tiles.