WHEW.
That ended up being fairy challenging by the end
At first I didn't really care for it because I didn't understand the dice roll mechanic of rolling hostile dies. Like my brain registered I could roll shit, but for some reason I thought it only applied to swords to hearts, or hearts to swords, and more mechanics would be added later.
I liked all the enemies designs and the differences in their attack values etc. I'd say the most frustrating part of the game was spam rolling dice and getting the same result while on a time limit, rather than guaranteed cycling into the next one.
The stun zones were also kinda frustrating, but that's part of the main challenge of the game I guess. I think if there was ever a full version of this format there would be a lot of potential for like, different attacks and defense methods, or support dice. Like you could either have an upgrade or equip system with your favorite styles of attack, or have certain stuff more effective for different enemies. But then instead of the time limit bar on the bottom ending the game, it could just be faster and when the enemy launches their attack.
So you could have dice like the hearts that can just cancel an enemy's attacks entirely, or freeze dice that freeze one of their attack dice for a round but don't remove it, so they could stack up if you don't end the fight quickly or deal with them later. You could have combination attacks that require like, Heart, Sword, Ice that could do special effects or patterns, that were either initiated by the order you pick up the dice, or better yet, Have an area of the screen you click to LAUNCH your attack, so if you pick up a specific combination you can just choose to launch it or cast your ability/magic etc. There's a lot of potential for cool stuff in a fleshed out version.
Like after getting used to cancelling attacks, you'd eventually find an armored enemy with metal or chains around his attack dice, and hearts would just bounce off unable to affect them, or would take a heart combination, or would need to be frozen.
You could also choose to remain simple where enemies just have healthbars like you do, or eventually have special healthbars that depend on their bodies where you'd have to physically aim, done through combinations or by clicking one of 3 spots on the edge of the field where you 'launch' your dice. I just picture like, launching a big Crescent projectile that would either be guaranteed to hit the weak spot, or hit multiple weak spots at once. Better yet, instead of launching dice in a direction, just have 3 spots and healthbars for special monsters being on different planes. could also work for multi monster fights where you have to answer multiple sides at once.
I know this is a lot, and maybe you have no intention of doing anything more with it. But those are my ideas since I see a lot of potential in it. Feel free to use them if you go on to make something more.