Level 12 has a task - Leave at least 5 cards in deck at end of game

As the task is to leave at least five cards in the deck when you have cleared the board, you can use the Booster +5 extra cards in the deck to achieve this. Level 12 should be doable without any Booster though. :)

Score needed for 1 Star, fetched by Nancy Kit Copp: 10,000 points