Hey,
As stated as the second sentence of the description. Each fight is 1 elemental dice + 1 heart dice representing the hp, the damage depends on the element each dice have.
I added more information about the dice in the description, hoping for people to read a bit more about the game when they're lost.
It follows the basic mechanism of a lot of games, elements have good/bad/normal matchup dealing damage depending on that (like in pokemon for the well-known one).
And same about the hearts, it follows the basic mechanism of the heart representing the life of the unit/player. And after each hit, you see hearts being removed from the dice, and well they are all removed, you lose that elemental dice and it goes to the next if there's one. And that's why at the end of each turn, there's the message "the remaining hearts" ^^.
That's always interesting to see players with different habits not understand some part of your game that is totally clear for the others (that's the first time someone mentioned they didn't understand the heart mechanism, either friends/players here/streamers). And that's why a large pool of playtesters is important :D.
I hope with that new information you give another chance to the game and you'll appréciate it ^^.
Thanks for the comment!