I’m hoping to make a kind-of board game in which you must eliminate all of the pieces exclusively owned by your opponent. A few possible twists:
A. After every few moves/captures, one of the sides of the board crushes inward, effectively shrinking the board as you play. This one is pretty certain to be the case, for compliance with the theme and to make the endgame work.
B. it is likely that any given player will have up to 1 minute to input their play for this turn, after which point the moves take effect. If you haven’t specified a move this minute, tough cookies for you; the other player will move anyway. Perhaps both players specify their moves during this minute, and the moves actually take effect simultaneously.
C. Perhaps the board contains some pieces that both you and your opponent control (?). Mutually exclusive with the simultaneous-action variant of B.