This is one of the most agonizing 100% completions I've ever tried to undertake. Asking the player to replay the game on Hard Mode is fine enough, but apparently the developers were not satisfied. Because you see, certain story options have 3 variations, those being the various dresses characters wear in Chapter 9, and a unique cutscene for each character in Chapter 14. Getting these requires making certain choices or completing a certain amount of side quests, mostly contained to Chapters 3, 8, and 9. To make this even more infuriating, those choices are not actually "saved" until you finish the chapter to completion. It's not a huge amount of extra effort, thankfully, but it still ends up eating up even more time. This means it will take, at the very least, an extra replay of Chapters 3, 8, and 9 outside of Hard Mode. But without proper planning, the player might be asked to play each of these chapters another one or two times. I lost count of the amount of times I played Chapter 8 in particular, which has a very large amount of unskippable story segments that eat up a ton of time.
Hard Mode itself, thankfully, is actually really interesting. Instead of being satisfied at just having enemies deal more damage and have bigger health bars (although they do also do that) there are some unique changes. Items are completely disabled, meaning that healing, reviving, and removing status effects are now exclusively the domain of various materia. To make that more limited, MP no longer gets restored at benches, only through random MP drops by breaking boxes or at the start of a new chapter. This means that you now have to consider MP management throughout the entirety of a chapter. A fully levelled Magnify materia paired with Cure thankfully makes group healing less of a concern (a fully leveled Prayer also does the job) as the 25% reduction is negligible compared to the benefits of healing 3 party members at once. But it still forces you to avoid playing recklessly to stay stocked up on MP, avoiding using offensive spells recklessly.
On top of all of this, some bosses now gain new attacks, though I wish it was more frequent. The only ones I noticed were the Hell House and Eligor. The Hell House now begins spitting out Tonberrys, forcing the player to divert their attention or else get taken out of the fight by the dreaded Chef's Knife. Eligor gets the most interesting change, casting Reflect on your party midway through the fight, making all support spells not just worthless, but a detriment, as they'll be reflected onto Eligor itself. My first attempt, I didn't realize this at first, and cast Regen on my party, only for Eligor to gain the Regen status itself. That fight is already hard enough on this difficulty, but the fact that it basically got back to full HP for free meant my defeat was all but guaranteed.
Genuinely recommend doing a Hard Mode playthrough if you had fun with the main game, I think it's a different enough gameplay experience to be worth it. I also used this as a chance to take a second pass on the story, but honestly, my thoughts aren't particularly different. Rebirth has the chance to take the new ideas presented in an interesting direction next week, but my hopes aren't high. Time will tell, I suppose.
Hard Mode itself, thankfully, is actually really interesting. Instead of being satisfied at just having enemies deal more damage and have bigger health bars (although they do also do that) there are some unique changes. Items are completely disabled, meaning that healing, reviving, and removing status effects are now exclusively the domain of various materia. To make that more limited, MP no longer gets restored at benches, only through random MP drops by breaking boxes or at the start of a new chapter. This means that you now have to consider MP management throughout the entirety of a chapter. A fully levelled Magnify materia paired with Cure thankfully makes group healing less of a concern (a fully leveled Prayer also does the job) as the 25% reduction is negligible compared to the benefits of healing 3 party members at once. But it still forces you to avoid playing recklessly to stay stocked up on MP, avoiding using offensive spells recklessly.
On top of all of this, some bosses now gain new attacks, though I wish it was more frequent. The only ones I noticed were the Hell House and Eligor. The Hell House now begins spitting out Tonberrys, forcing the player to divert their attention or else get taken out of the fight by the dreaded Chef's Knife. Eligor gets the most interesting change, casting Reflect on your party midway through the fight, making all support spells not just worthless, but a detriment, as they'll be reflected onto Eligor itself. My first attempt, I didn't realize this at first, and cast Regen on my party, only for Eligor to gain the Regen status itself. That fight is already hard enough on this difficulty, but the fact that it basically got back to full HP for free meant my defeat was all but guaranteed.
Genuinely recommend doing a Hard Mode playthrough if you had fun with the main game, I think it's a different enough gameplay experience to be worth it. I also used this as a chance to take a second pass on the story, but honestly, my thoughts aren't particularly different. Rebirth has the chance to take the new ideas presented in an interesting direction next week, but my hopes aren't high. Time will tell, I suppose.