Plutonian Poker is a set collection game for 2-6 players that uses Looney Pyramids. Players claim pyramids from a shared pool, building scoring combinations with their claimed pyramids. The twist is that you are not allowed to rearrange your claims once you've made them, making the more complicated and valuable sets riskier to achieve. Rules here: http://icehousegames.org/wiki/index.php?title=Plutonian_Poker