Really, if I'm being honest, no main series game, aside from some specific battles, made a pokemon game hard for me. Pokémon games are very easy, and are only beginning to be made easier.
Although, I guess this is situational? Sometimes I have a hard time in a Pokémon game because I do a lot of Egg raised Pokémon only runs. Those are difficult, especially if you aren't lucky and don't get egg moves.