Fun game, challenging puzzles, an honestly fantastic mobile game design. Why rated so low? Because it becomes increasingly clear that everything is engineered to drive to towards purchases in the game. I mean everything! It's -so- much fun at first, but so quickly you realize everything costs -something-. Need five more moves? Buy coins! Need an advantage in boosters etc? Buy packs! The game is so well-made. Wish it wasn't so geared towards trying to dip into my pocketbook -so- frequently.