Same concept as most match 3, etc games. And entirely too many ads! I don't care for how they've tried to turn just about every game out there into some sort of "quest" or "mission" type game. I don't like how they increase the levels to such difficulty at some point that you just about can't beat the levels. It makes it irritating and frustrating, instead of fun. And so it makes me want to delete it, instead of continue to play. Just another time waster.