Sometimes another event starts before one finishes, which means you don’t earn the tokens from the previous event AND you have less time to finish the new event and earn tokens from that. It’s frustrating and feels like the developers are cheating. Other than that it’s an ok game. It’s quite easy, but it kills time and is strangely enough addictive while it doesn’t let you play forever without spending actual money (which I won’t), but you won’t get stuck on a level forever either, because you earn tokens to play with every day.