Things you really nailed:
The game feel. The clicking sound of the dice incrementing is great! I love the little hour glass sprite you used before it starts a 1, it was a nice little touch that helps provide feedback.
Camera shake felt just about right, not too much and not too little!
Fire and impact felt good, enemy knockback felt great!
The mechanic is clever!
There is one fundamental issue with the mechanic however:
Essentially all you really have to do is gather the enemies into a big ball, and just keep using the single pip attack. This will always whittle them down and kill them. I thought perhaps the detriment to this was speed, but there really isn't anything stopping me from abusing this and waiting to match each number would technically take more time and involve more risk to the player than simply dodging, circling, and spamming the 1 pip attack.
Does this mean that the mechanic is bad or not reworkable? Heck no, but it does need a bit of tweaking. Maybe you could tie the speed of the enemy to it's health value? 1 pips are slow, higher pips are faster? Or vice versa? It will take some experimentation, but im sure you could refine this even more and I'd love to see more variety!
Overall though, great work! Wanting more just means you have a solid foundation! :D