Very nice game! I'm glad you kept the scope down, seeing as you only managed to submit a few minutes before the deadline! :D I love Die in the Dungeon and Slay the Spire - both games you mentioned as inspiration.
Overall, I enjoyed myself, but the battles got very grindy. The risky strat of taking new dice with more skull chances seems to heavily weight in favor of a sudden backfire, but the safer strats got way too grindy with only low rolling dice.
I'm not sure how you got the screenshot for floor 20 - maybe I just needed to get better luck on the rewards and earn more skull slots? I hope you continue. Some new dice ideas would be some kind of boosts and multipliers for attack and damage. Different styles of attack like venom, fire, or lightning could also have their own attack values and boost or nerf other types.