Love the concept. The art looks nice and fitting. However, the mechanics were too easy for me. I think what you can do is to make this a turn-based game where enemies get to attack you. That means that you'll have to increase the player's HP like 40 or something. To compensate for the damage received at each round, you could either give the player some reward at the end of each round or give the dice some type of powerup like healing the player or hitting the enemy at twice the amount. Other than that, I think it's a fun and simple mechanic. Well done mate.