If you wanna waste approximately half of your life watching ads for the same things over and over again this is the game for you. Each level is relatively simple, and there isn't really a difficulty curve, I played through 250 levels and the background will change, but you will do essentially 30 puzzles in random order over and over again, even the boss fights, there are maybe 5 different types of boss fights, so you just do the same puzzle again and again then watch the ads again.