What is the hardest level in Royal Match?

I'm curious, what is considered to be the most challenging level within the popular puzzle game, Royal Match? Are there specific obstacles or requirements that players need to overcome in order to progress to the next stage, or is it simply a matter of luck and persistence? Have any players shared their strategies for conquering this seemingly insurmountable level? It would be fascinating to gain a deeper understanding of what makes this particular level so difficult for so many players.