I must say I really love the overall look of the game. Maybe a type of currency to buff the dice mechanic?, passive abilities for units in the shop would be nice to make this more of a strategy/survival/roguelike game.
More enemies and units would be cool of course.
By the way, your game reminds me to one called Auto NecroChess (love it too) https://stopsignal.itch.io/auto-necrochess