About COAL, from BoardGameGeek:
Sixty-four square tiles display eight shapes, eight tiles for each shape. Four tiles are dealt to each player, and one tile is turned face-up. On your turn, add one or more tiles to a line of face-up tiles so that either all the shapes in the line are the same or all are different. Score one point for each tile in a line of different tiles, and two points per tile in a line of identical tiles. Double your score for a line of eight tiles. Replenish to four tiles at the end of your turn. Play until the tiles run out. Most points wins.
