-Way too much text up front, I'm not reading all this shit by you.
-My first intuition with the movement was to drag the card onto the location on the board that it would move the piece to. It had me confused because the circle then disabled -- don't limit the range of the mouse when selecting movement direction maybe?
-UI is slick as shit but you're not handling basic cases like picking invalid moves in the circle, it's not responsive. Color those parts gray and not let them be selected or some shit.
-Queen being forced to move the whole way is not intuitive (same issue as before -- I'd expect to move on the board locations, not the card).
-Tried moving pawn diagonal -- not only you aren't preventing the move, you're executing it in a way that looks like it worked, even though it's not a valid move.
-All that fucking text and no difference of the shield and lightning paws mentioned in their identical descriptions, good job
-Staying in the last row doesn't automatically convert the pawns to Queens
-No clue, what the "last" row means by default
-The brain enemy feels out of place, as does the shop, which I have no idea what it does, this is a deckbuilding game now?
-There's some lag on the web version on the endscreen

It looks great aesthetically, it's smooth and it works fine, but it doesn't feel fun, or at least doesn't live up to what I was expecting from it, whatever that was. I don't know man, maybe it's the lack of lore, kinda feels like you are trying to make chess secondary, but the primary appeal is sold as the chess being a large part of the game.  No idea how I would improve it from this point either, would probably scrap and restart.