

Tbh it’s a reflex and dexterity game, among other things, so it is not for everyone. In the same way a game that requires memorising melodies is not for me, since I suck hard at it.
I suppose there could be a mod that simply doesn’t let you die and you can explore the whole world. There is no other way to make a platforming section easier, unless you add more anchor points etc., which requires actually changing the world (essentially, you remove the platforming section), so those could still be a problem.
I have never heard of the game, i guess you are referring to https://celeste.ink/wiki/Assist_Mode?
I can see they have lots of options! However the platforming seems to be slightly different? In case of HK I suppose that invincibility-like mode is what I suggested brought to the extreme (I.e. you can just walk over spikes etc). Maybe the other thing that could work is slowing the game down so that timing is easier to get.
I think it’s an interesting discussion accessibility from this point of view. I think everyone draws the line at some point, between accessibility and simply making a game with some principles that represent the soul of the game.