I absolutely love Diggy. I started playing in 2016 and this game has not once lost it's luster. The developers continue to add new challenges and an ever expanding panoply of puzzles. The developers do not constantly bug you to buy stuff, and the game is not one of the pay to win games. There is a slight learning curve, but once you get into the game and figure out the puzzle structure it's a breeze. So if you're looking for a game with challenges and rewards I would highly recommend Diggy's Adv