Hey, look, dont even listen to Whisperknife...
He's apparently suffering from lack of understanding the game. Some might never fully understand it at all...it's not like you made it super hard (except the last level on normal and hard mode... you might want to better develop your difficulty implementation.)
I can understand how someone might get bored with defense games in general, but just because you have basic units you tend to use alot doesn't make it boring... strategies become different with the layout of the maps. (you used WAY too many archers, though, I agree... they were like kill all kind of attackers... the only unit capable of even possibly defending against them were Manticores, which were actually weak against arrows. Actually quite a big issue... you seemed to use them as a crutch.)
And if Whisperknife even bothered to play past the first two levels (doesn't seem like he did) he'd know that your Lord of Death, Destruction, and Decay was the best way to deal with MANY things. He is actually your best hope in the final level, along with digging out a proper path for your enemies to funnel through. Trust me when I say this: Focus on yourself (Artificer, Back in Black) and you will kick about 30 different kinds of ass, especially with Artificer. HASTE is your friend.
All in all, a pretty awesome game. The music seemed fitting (although more variety would be appreciated, and better samples for the instruments you used... I'm pretty sure you used FL studio default samples for the music... not so great).The gameplay and interface were pretty spot-on for the most part. Definitely could have used a MAP EDITOR.
I really DON'T appreciate the fact that you could only get special abilities on Kongregate (along with access to the Wizard) that's like a slap in the face to the average NG user... it pretty much hollers "Hey, go to Kongregate to get these things that you can't get here because they PAY for me putting my games on their site. I'm just posting this limited version here because I want to tease traffic so I get more money."
Not that there's anything wrong with money, mind you. I.... just think things like that should be a bit more subtle. If I was wrong in my assumptions, feel free to correct me.
5/5
9/10 (because this isn't even the full version.)