Hey, thanks for the feedback! Honestly, I think I somehow made pawns the most overpowered and broken part of chess with this haha!
You raise a good point about having some visual effect to show when a piece is too expensive/high ranking to move. I think a combination of your suggestion where expensive pieces are faded out, as well as maybe some indication of how many points a move will cost could work well to communicate this. Should make things a bit less awkward.
I think once the voting period is over, I'll likely create a more complete version of this game with all feedback taken on board.
Thanks again for playing! :)