Snowflake (1971)

From the introduction – “An assortment of interesting puzzles and games based on a mathematically closed set of ten pieces and a clever but sometimes frustrating base.” The pieces are each three or four hexagons jointed in various combinations to create ten different shapes. The most interesting game in the group is called Glacier. Players take turns either placing a piece on the base or moving one that is already positioned. All empty spaces must remain connected. It is not legal to close off an area. The last player to make a legal move is the winner. The puzzles are generally of the Tangrams type.