Computer lacks intelligence making this game to easy, on the other hand, if the computer would play logical every game would end in a draw. 1 star, sorry.
I liked the idea, but just matching up sides becomes rather tedious after a while, there are no really new elements to the puzzles, they just take longer.
The towers quite often ignore the first enemies allowing them to pas unopposed. This is unacceptable for a tower defence game. Difficulty is not a problem. 2/5