This is really good. the pixel art beautiful and the colors well chosen. The gameplay is simple and fun, upgrades feel meaningful. It gets very intense after a while.
If you want to work more on the game after the jam, try making the tutorial interactive- it is confusing to learn the rules from the wall of text. Also, I had a hard time distinguishing between the praying and not praying souls with all the stuff going on.
Overall the game feels great and polished, very well done.