A pretty simple and fun little boss battle. Given I'm a bit of a shooter veteran, I was able to smoke the guy no problem--but I didn't come here to wank off my superior gamer genes.
The presentation of it was really nice! A low-poly look with flat textures made everything pop out, and the Demiurge himself was sufficiently spooky. Very cool. The wand looked like exactly what I would expect from an indie rendition of Heretic, and I liked how you could shoot the attacks down.
Seems like the rain from above requires pure luck to dodge; there's the floating platforms in the distance you can jump to, but recognizing the attack and making it there in time is an extremely narrow window, so it's just easier to eat the damage. Thankfully the gem's there to help heal, which I like a lot! Putting yourself in the open area and risking more damage or making use of cover and taking less damage.
That being said, I stayed hugging the crystal pretty close anyway because of the lack of slopes in the area--a lot of times I would be backpedaling away from an attack, only to hit a snag on the wall and eat an attack to the face. And it didn't taste good, no sir.
Still, a fantastic game and a good product. I'd be interested in seeing more of this, if you decide to pick it up again! Congratulations on making it through the gamejam!