The game isn't bad, but it isn't good either. It's definitely more good than bad, hence my 3.5 star rating, but it lacks a variety of things - like a more dynamic gameplay and a more relevant upgrade system. A fast forward button for the battles would be really nice, since just watching the battles is really boring and time consuming before you have any spells. It's fun to play for a while, then it gets very repetitive. It's not even frustrating or annoying as some defense strategy games are - some people, myself included can take energy and drive to win out of frustration - it's just boring.
Anyways, not a bad game, it's worth a try. :D