Cool entry, and very nice to have custom keybinds.
I also like the presentation, these 3d models are nice, and the fact you gave each enemy its own color scheme makes for quick distinction when in the middle of the action.
My main issue is the difficulty balance, the fire attacks don't seam to do a whole lot of damage or have that much range even after the upgrade so i found it quite hard to kill enemies without taking massive damage, i managed to reach "brain drain" on normal difficulty but got overwhelmed imediately and couldn't do anything with the mage draining my power. Another small issue is the camera that tends to clip through walls when too close.
Now with that said the game's still good, i feel it doesn't need all that much ironing out cause the base mechanics like the aiming and movement are pretty solid as is.
Overall well done :)