You should add snapping to the dice so that they can't just be set anywhere.
In general, the game seems pretty good. One idea that I had that could be good is you have two or three dice, and you can spread them out between different stats, and then when you attack/fight/whatever, they roll and your stats are increased by the totals shown. And then if you wanted to attack, you would place dice in your attack field, or if you wanted to increase defense, you would place them in your defense field. The reason I suggest this is because it is very hard to attack, and also to gain stats. This would help remove the importance of combos, while not making them redundant, turning them into a kind of bonus. Also, I would recommend regaining energy more often, or regaining more at a time, because you often have to waste moves waiting to get more energy.
I might take a diffrent aproach. For now Im looking into making combos a mini-goal for player to reach during combat. In terms of energy regeneration. Im working on it. You will have the ability to forsake your move in order to regenerate your energy. Hopefuly this will make for a interesting decision for a player