After reaching level 3, I had already watched so many ads that I uninstalled the game. The puzzles are extremely easy, and the ads are each around 30 seconds. Ads are to be expected, of course, but the amount on this game was too much for me. An ad after each puzzle. I'm sure you can pay for a no-ad version but I certainly would not, as the game is either for very slow adults, or perhaps children.