Bowser's Revenge 4 has 8 Worlds and an additional Star World, and several unique bosses made specifically for this game. There is quite a fair bit of custom ASM, especially in the Star World, which should make this an interesting experience. The difficulty varies as it's fairly easy in the first few worlds, but difficulty increases a bit past World 6, especially in World 8 and the Star World. Unfortunately, I can't choose both Standard: Hard and Standard: Normal, but just know it gets more difficult as the game progresses. As for the bosses, none should be too difficult or too confusing... maybe.