Atom-4 is a two-player color manipulation game played with colored
 spherical pieces on a board divided into equilateral triangles. The
 player who first makes a row of 4 pieces of the right color wins.
 However, the players do not directly play pieces of the winning color;
 they must construct their winning pieces via color changes that happen
 to neighbouring pieces whenever a new piece is placed on the board.
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 Atom-4 supports both a curses-based text interface and an X11 interface.