Terraforming Chess

Chess, but your forces wield terraforming technologies, restricting the play space as turns pass.
Rules are as normal chess, with the following changes. As such, you may also play this game with a physical chess set, so long as you have extra markers for Wall, Pit, and Ice tiles.

Pawns are now Workers. They retain their special 2-space move, can perform En Passant, and can be promoted. In addition, they ignore special terrain types, restoring tiles they enter to normal.

Rooks are now Extruders. They create a Wall tile in the space they started in which blocks the movement of all pieces except pawns and knights. Castling, while not technically disallowed, is functionally impossible due to the king ending on the bishop's space, which is almost guaranteed to be a pit. As such, our game does not implement castling in any way, but feel free to use it on a physical board.

Bishops are now Sappers. They create a Pit in the tile they started in that capture any pieces except pawns that stop on them. Kings cannot legally move into a pit, thus they can be used to checkmate.

Knights are now Cryoformers. They leave tiles of Ice in the space they started in, which causes pieces that would stop in that space to slide. Pieces that slide cannot capture until they stop sliding. Pieces that slide into a wall/board edge stop, even if still on ice. Pieces that slide into a pit are captured.

Queens are now Mass Transmuters. When they move, choose a tile type. Queens transmute every tile they pass over to the chosen type, except the destination tile.

Kings are now your Terraforming Core. They can, instead of moving, change an adjacent unoccupied tile into any other tile. Kings can transmute tile to remove the King from check. As the algorithms for check/checkmate are complex and our time and energy are limited, we have not implemented check nor checkmate in our code. The game still ends when a player's king is captured.

Bugfixed version makes some buttons easier to click and fixes the piece order.