Tried it out and not sure if I was missing something but I could never find any souls.
I collected the lantern and could flip it. The angel would start chasing me. I could see the dimension portal and two balls of light over the altars to the left and right, but I didn't find anything else that looked like I should try to interact with.
I'm playing on the web build (in case there's something maybe not working specific to that. Or maybe I'm just missing something.)
From what I've seen, it sounds like an interesting idea, balancing the angles chasing you and rescuing the souls.
The only real complaint was that the walk to the hourglass did feel a bit long. There's an argument it was building the atmosphere, but even for that it did feel a bit too long, especially the walk into the cathedral at the very beginning.
(Though that may just be my expectations. A lot of Jam games seem to throw you right into the thick of it.)