Huh, this is weird. Feels like it should should be pretty much up my alley, but something here isn't quite clicking for me yet. I'm not sure exactly what it is, but I think it might be that I find the game to be lacking a bit of character. The sprites are fine (apart from being a bit hard to instantly identify, which would be nice), but not outstanding and the playing field just being an abstract blue grid doesn't really make me feel as if I was in the midst of an epic battle. Maybe going for something a little less abstract would help me to feel more engaged in the game.
Now, let's get to the nitpicky stuff:
The first thing that comes to mind is that it is very overwhelming on startup. Pretty much the first thing you're supposed to do is pick 8 characters and I don't even have any idea why or how the game works. I do like that there's such a variety of classes, but maybe don't start with all of them available from the get-go. Unlocking classes might also be an interesting meta-progression thing.
After I clicked auto and play for a little, I actually managed to understand the game pretty quickly. But yeah, adding a short tutorial mission the first time you play might be a good idea. Also, apparently you want to add a campaign mode? I fully support that!
Generally, I think that the game feels a bit too random and there are not enough ways to counteract. A lot of times, I found that my dice just weren't good to do anything useful. A few ideas how different dice could be made more useful:
I feel like movement is a bit limited and I think I would enjoy this game more if I could move up to n squares instead of exactly n. At the very least, you should allow me to reach squares of the same parity, as I should be able to just move back and forth.
I wonder if it might be more fun if there were a few characters that crit on something else than a 6. Like, the Rogue feels like a perfect fit for a 1 critical. Maybe I've just played too much Dicey Dungeons, though.
I would like if I could direct my attacks, though I do appreciate that the Rogue can backstab. That way, there's more chances for classes with small AoEs to hit something.
Finally, if none of these appeal to you, maybe add an extra die and you have to discard one die every turn. That way, there's a little less variance, though I also do appreciate that it increases the complexity of the system
It's a bit annoying how little you can do on your first turn but try to collect the coins. Maybe a sort of summoning sickness would help? That way, on your first real turn, there would already be enemy targets available for you.
I would really like to have an end turn button. Having to spend your unusable dice feels a little frustrating.
I read the description first and red vs orange was pretty confusing for me at first, and I figured a critical hit would always deal two damage. I like the way you do it in-game and you should probably use that for the description, too.
Balance seems fine in general, but a few things should maybe be adjusted. For example, the Swordsman (almost) seems strictly better than the Axeman, apart from a 4 roll. It seems like generally, 2 damage is a lot stronger than AoE, since I found enemies tended to be too spread out for it to be really worth it. Also, the way coins are generated now, it kind of incentivizes low-cost unit spam in order to maximize your chances of collecting them. In general, I think a different way to earn money might be nice, but I'm not sure how exactly. Maybe just a passive income?
Final nitpick: Pretty sure "dice" is already the plural, so "dices" is wrong.
The shrinking battlefield is a really nice touch, I like it!
Once again, sorry if this sounds overly negative. I do like the concept and the systems at play here, and I do think this could turn into a fun strategy game with a bit more work.