A game that bucks the copycat match-3 fad and presents a deep puzzle that is completely fresh. Primrose's gameplay is deceptively simple: You're given random pairs of coloured tiles that you must place on a 7x7 grid. When you surround a group of one colour with another colour, the surrounded group clears, scoring points. The surrounding tiles flip to the colour of the tiles that were cleared. When tiles flip color, chain reactions are possible. Larger groups and longer chain reactions are awarded more points. As the game progresses, more colours are added to the pool, making the grid more and more constrained. Pressure builds until the grid finally fills up, and the game ends. Despite this mounting pressure, the game doesn't have a frantic feel, because you have as much time as you want to make each move. Primrose derives deep challenge from inherent properties of its core mechanics, not from time pressure or other external gimmicks. The game also features a world-wide online high score board complete with instant replay, move-by-move, of all top-scoring games.