I am on level 50. There are some levels that make you think, and some that are quite easy. And some that look complicated but then you go “duh!” when you suddenly realize that you are making it much harder than it is. All of which makes it kind of fun. Each time there is a new type of challenge, it shows you once how to beat it, then you figure the next one out yourself. Overall, there are more fairly easy levels than hard ones, but the difficulty is kind of mixed around, so that you get a real easy challenge, then one that makes you think, then maybe one that you have to retry. You never know what you are going to get. Plus, of course, everyone’s brain works differently, so what is easy for me might be hard for someone else, and vice versa. Overall, I have found most of the levels pretty easy, but there are enough others that I have enjoyed the game so far.
As to the complaints about too many ads…put your device on airplane mode, and there are no ads at all.
The one thing I don't like is that if you pass a level, but not with all 3 coins, there seems to be no way to go back and redo that level to get all three. I have only missed three coins once, but saw how to do it better - only now I can’t. Very annoying.