The puzzles in the challenge section are actually decent, but the experience is detractrd from with the repetitiveness of the main gameplay and the near constant ads. Not to mention the agravation of it giving you the option to willingly watch ads to receive a game item but 50% of the time you get a bs error message saying there aren't any ads available or to check your internet connection and when you finally get fed up and click continue, you get shown an ad anyway without getting a reward.