Too connected to ads. You get a gift but if you dont watch the ad, you cant open it and it is lost. To force you to watch the ads, they even made a seperate page where you must confirm the gift as failed before you can continue. Same goes for the challenges - if you fail one, you must watch an ad otherwise you cant retry and if you are unable to do so, you are locked out from the level until you do it. Overall an easy game. Got to about level 80 but meh, not interested to continue.