That reminds me of this old, obscure SMB romhack called AIR which is loosely based on the VN of the same name. You only get one life and can jump in mid-air infinitely but that doesn't make it any easier: you also need to know the game inside out and be skilled at pulling off different glitches to beat it. This is a tool assisted speedrun so obviously it powers through the game but it's a lot harder than what it looks.

ROM hacks that are clearly made by people that really love a game and want to spend more time in are pretty awesome. The most common is probably the 'randomizer' that seems to be hugely successful for streamers and it leads to tournaments and other things which highlight the player's knowledge and ability to adapt to things.
They're cool, but a handcrafted thing will always be better I think. Another cool thing with these rom hacks is if you buy a flash cart thing they're playable on actual hardware. I would have killed for this stuff to be available back in the day when these consoles were new. Imagine staving off boredom with all this stuff!

hard section... here you have to race kamek and prevent him from reaching the left side of the screen, and the bit at the bottom is an obstacle course where you have to use melons and eggs to melt or kill stuff and you have to spit enemies at other enemies and theres no margin of error. the stuff right above yoshi is instakill blocks

the whole romhack is like this
that and a looooot of timing puzzles
timing is a pretty solid thing to build a wide variety of puzzles around because all the different elements you can use in yoshi's island have different delays and speeds. theres a lot of richness