I just started hard mode for the main game and am already somewhat struggling in chapter 1 lol.
For Intermission, I finished the main story on hard but I'm yet to complete Yuffie and Sonon vs Top Secrets. Had a blast figuring out how to deal with the first super boss, who forces you to use a variety of character specific dodges/blocking/parries to survive him, while also forcing you to be aggressive. Such a satisfying mix of defense and offense. One mistake at the wrong moment (like retrieving your shuriken when your intention is to throw it) can easily snowball into defeat. It's a thrill.
And to clarify on my comment on visuals: This game does look gorgeous during its better times, typically metallic environments and glossy materials at night time. It usually doesn't look nearly as good at day time and wider rocky environments (unlike Rebirth). Boss fights like the Airbuster looked stunning down to the smallest details. It's CGI like.
Another thing I said that needs rectifying is my comment on story changes. The "Whispers" aspect and the ending can fuck off, but so far I love how they're treating Yuffie and Wutai. She's no longer just some optional goofy ass cutie with little to no depth.