Fantastic game. I like how it combines chess with rouge-lite in an Autochess-like fashion. The animation is very nice, though it is a bit long if you are replaying it over and over again, so I'd like to see an option for faster animation or even skip animation.
Maybe at some point you could prevent the user from putting themselves into check/checkmate.
Some points about balance: I managed to start a session of with two enemy queens vs my king and princess. Not sure if that is beatable. Also I feel like the original chess pieces just feel very valuable at their tier with the exception of the pawn. Because reaching the other end of the board gives you an essentially dead character.