At first glance this looks like a "bullet heaven" game, but I found it much more tactical and engaging. The contagion of vampirism spreading through the crowds makes for an interesting dynamic, and the different types of hunters keep things fresh. This is quite challenging; I played through it 4 times and never got past the Inquisitor stage.
The graphics are clear and the different units are distinct, but there's no environment or sense of place. The audio is serviceable (the SFX play when something significant happens!) but a bit of music would have made this more atmospheric.