I tested out a few runs and lasted about 15 seconds in each one. The first room would absolutely demolish me since I couldn't clear the enemies fast enough. I tried out several weapon combinations (using both hands, of course), to no avail.
Probably could benefit from easing the player in a little - generally all horde shooters start off with 1-2 enemies just to see what their speed/AI is like, before spawning in hundreds of them to mob the player. I like the weapon selection wheel and different magic types, but I didn't last long enough to give detailed feedback.
The room designs are also very cool. Reminds me of 40K games with giant cathedral buildings and what-not.
Either way, this is definitely a game I'll check out again since I do like horde-shooters