Only your own pieces count as neighbours when deciding births/deaths.

For births, an empty square must have 3 neighbours for 2 consecutive turns.

For deaths, a piece must have <2 or >3 neighbours for 3 consecutive turns.

This is a simple proof of concept I made with python and curses.

You can play with a friend locally or over a socket connection.

Controls: Arrow keys to move the cursor, enter/space to select and move a piece, u or backspace to undo a move, r to redo a move, q or escape to quit, s to perform a move with stockfish if installed (useless since it has no knowledge of this variant), any other key to unselect a currently selected piece.