I had no idea this would be a defense game. It was quite good! The best part is how it's so easy to understand. I like the squeals of the rats as I kill them. Dang, that sounds sadistic. It's just really fun to play.
I'm glad there's the "speed up" option. It seems to go pretty slowly on its own. It was interesting to have more complicated enemies. It was also cool to show the enemies health on top. I wasn't expecting only the mages to hit flying enemies.