A 5th Martian Coaster with black squares and gray arrows is a special promo card that allows for a 5 player game of the Looney Labs game. Martian Coasters is an Icehouse game playable with a single Treehouse set, a set of Martian Coasters (each with a colored 3x3 maze printed on it), and a standard d6. The coasters are arranged in a square and the pieces are placed on differently-colored coasters. The objective is to move the pieces of your color through the maze printed on the coasters and onto a goal square at the center of your coaster. The game additionally makes use of the Treehouse die, allowing the players to reorient and move the coasters, creating a constantly changing maze.