Very addicting little game, I could see myself as a kid spending an afternoon playing this on Congregate back in the flash game days. My biggest critique is on the sound-design front: when multiple sound effects trigger at once, they stack to become quite loud and completely overpower the music. I would suggest limiting the number of simultaneous SFX (at the end of the level, when the ritual is completed, the sound of every enemy dying at once for example is extremely loud).