Its a fine game, I play it to help me get sleepy sometimes, so don't think it's challenging. What a ripoff to remove ads, $4 only to remove between level and banner ads.. still am forced to sit through the "earned prize" ads every 5-7 levels. Can't play in airplane mode either unless you don't want the coins at all. The event pieces also take wayy too long to reach and progress gets reset anytime you close the app? What's the pont? Can also lose levels bc pieces miss the goal..even if no errors