I liked aiming for headshots!
The models for the enemies were nice. I liked the environment though it needed some other colors. The shot particles could use a little more effect, it really doesn't feel like such a heavy shot when you see the particles coming out on a wall. And some shadows underneath the enemies would be neat!
On the audio part, I can really just comment about the shotgun sound, which was good, felt like packing a punch. The game could really benefit from an eerie background music. It's hard to keep track of the mage's shots without sound.
It might be just me but I thought the mouse sensitivity was a bit too high, it got a bit confusing running around sometimes. The reload button was never used since the character always auto reloaded after every shot. Also, do the knights die?
Once one mage spawned above the ground, sort of as it was levitating. Not sure if it was due to spawning over somewhere with an obstacle or if it was intended. Didn't hinder the experience in any way though.