Create a square of any size connected by lines.

Each player starts with 7 stars. On your turn, you can play a new star of your color on the board or move a star of your color you played previously. If you move, you go to the next square connected by a line. If this square is empty, nothing else happens. If this square is occupied, push the star no matter its color. You can't push more than one star. You can push stars outside of the board.