Very fun game. I greatly enjoyed the theme. Evilness is fun.
I'd have loved to see more effects of my evilness- burnt villages, dead families, etc.
The artwork was generally pretty, and fun to see.
I liked the music. You've always had good music in your productions.
The lack of any control was nice. Meant you could just be an overwhelmingly powerful warlord. Some customization would have been nice, though. Different paths to take. Like, two different upgrade paths for each tower.
You are awesome developers, and I thank you for this great game.
I'd add one or two things though-
Add some sort of random delay or increase in the firing speed of all towers. They fire at the same time, so it's pointless having more than one fire tower- it just does damage to one foe.
Increase the aoe of the fire tower, so, relative to the magic tower, it's more effective.
Decrease the cost of the arrow tower. It's kinda pointless when it's the same cost as the others.
Depower the magic tower slightly.