The basics are there, but this game needs more explanation of what the towers do and which towers are effective against which enemies. For instance, there is no clear way to determine which towers will hit an airborne enemy other than trial and error.
Also, when you click on a tower you must click again to cancel out of interacting with that tower, which is extra work and a function unneeded, just allow me to click around easily.
Bottom line, this game has good bones but needs more work in description. More details on the towers and enemies.
The music could use some work too, but that is easily fixed by playing your own soundtrack in the background.