During a game, to the right of the board, it will snow.  This has absolutely nothing to do with Halma, but it’s fun to watch.  You can control the speed at which it snows by selecting “Andante,” “Moderato,” r “Allegro” from the “Snow” menu.

On color Macintoshes, you can also select the starting color of the snow from the “Snow” menu.  Snowflakes inherit the color of the snow they stick to, although you can select “Mutations” from the “Snow” menu to have snowflakes occasionally pick their own color when they stick.  Other snowflakes will then inherit the new color (unless they themselves mutate).