This is very cool! I've seen other "capture a piece and become that piece" themed chess puzzles, but holding onto captured pieces as cards gives it a whole new dimension. And very good level design too: that last one definitely took some thought to maneuver around the defenses. Overall, excellent!
Skimming through my browser history:
- https://hmnafterall.itch.io/echochess
- https://hellolorem.itch.io/kings-court-chess
- https://threethan.itch.io/chesscourtquest (This one is a little different because pieces aren't removed, and your goal isn't capturing but moving the king to the flag, but it does have the "become the piece you capture" mechanism)