I have two big problems with this game
First, whenever you do a spell, Argus stops doing whatever it was you told him to. There were many occasions when I sent him to go fight and told him to throw lightning at a far away foe. He stopped moving and did this. These ranged attacks shouldn't stop him from moving.
Which leads to the second problem. Argus loves to stand there and get his face filled with arrows. A group of melee fighters will get cut down by Argus because he attacks anybody who attacks him. Archers however don't elicit this response. This causes Argus to die. Pathetically easily I might add. Also when enemies are focused on the gate Argus will just stand there unless you click on them one at a time so he can shuffle over and whack them with his sword.
You need to give Argus a range in which he will attack all enemies. This will stop him from being killed by archers who are standing 2 feet from him because you have to click on them one at a time.
You've got some interesting mechanics here, and it reminds me of Diablo, but that's not necessarily a good thing for a defense game. Diablo was about exploring, this is the exact opposite. What you need here is automation and streamlining, not frantic clicking on each enemy at a time. I was annoyed that some magic also only killed one at a time, and there was no way to upgrade these.
Lastly, this game is too repetitive, and I was bored by week 5. This is the worst thing that can happen in a defense game, which is normally a longer, slowly paced game. If the player is bored, all the fancy artwork, voiceacting, and writing(all of which were very good!!) will not save your game.