I love the atmosphere a lot, especially in the second battle! Feels rather like Inscryption, and I love that.
I wish there was more stuff in this demo, though. Maybe allow the player to beat the tutorial boss, and add ending cutscenes at the point where you beat both bosses? More importantly, perhaps the game can be balanced, and rely less on random chance, by giving the player an option to affect the dice rolls somehow? Maybe even give them an equivalent to the evil dice face (or whatever it is) so that they don't start off at a disadvantage? Either way, I can see the vision you had with this game and I'd love to see it grow!