Some of the modes later add additional or different sorts of challenges. Each mode is more a variety of game-play. We found some players just like to relax and make combinations without having to deal with enemies, and so the temple mode is geared towards them. Factory mode is more timed based and short goal based. Complete the following goals under a given time. And puzzle mode is pre-designed puzzles. So all the stuff you get to later is "different" and not necessarily harder, though in some cases it can be. (factory gets quite hard for instance)