I had the same critical bug "Tulenväki Productions" described, so I played the post-jam version, I hope you didn't change anything other than fixing that game-breaking bug, because that would be unfair to the other jammers, rating-wise...
Anyways, presentation-wise, the game looks very good, much better than most jam games.
About the gameplay, as you mentioned it's somewhat similar to my game. It took me a while to figure out how the roll-each-heart-to-check-if-hit mechanic worked, and that the character in the middle of the screen is the opponent and its die-sides, after figuring those things out, I think it's pretty clever. One downside for me is that there really aren't any choices to make accept for the initial choice of "die-sides". I think the game could be more interesting if you could see the upcoming opponent in advance, and build a die specifically to counter that opponent. Also it probably would be an improvement if there were any choices to make during combat.
From a UX perspective, the game is way more communicative than mine, cudos for designing it in a way to that helps intuitively understand what was happening. I was too bogged down in getting the core mechanic to function that I never got around to working on that, but it's super important.