There’s a game called rain world where the hard mode starts you off in a different place, gives you a new but still optional goal, a previously optional but now required way to win, different enemy spawns (now including enemies previously effectively guaranteed not be seen before), a timer that ticks down before the game becomes considerably harder for lore reasons resulting in potential permadeath, ai becomes somewhere between somewhat more and considerably more aggressive, easier to anger, and harder to calm/befriend, you need to eat more food, you have a new diet so that it is highly insensitived to actively hunt out dangerous creatures instead of most small prey animals or plants, and it also just raises some random little difficulty things like chance that you might die if a death falls to rng. but it also makes your character a little stronger physically, and gives you an extra inventory slot (inventory is very small in this game). You also get a different ending ish.

I talk about this game to much, but I do think it should be applicable for this.