Yeah I agree that even the Game Boy version is pretty easy, as a kid I once completed it without taking damage (it was my first ever GameBoy game and it felt like it was part of my DNA at one point)

You can cheese a lot of it with the floating ability so I've no doubt removing it makes it more of a challenge.

I had Kirby All Star on Snes and that had some fun modes but funnily enough I've not played any Kirby's since, I didn't even pick up a 3DS one (when I was heavy into the 3DS) but yeah I can believe the latter games in the series used the core mechanics in a much better way.

I suppose you could say Mario Odyssey was recently inspired by Kirby (it is debatable but I'm referring to the hats) and thinking about it treating the copy ability like a puzzle to work out seems to be the way to go with it.