I think what makes The Lost Levels stand out isn't so much the raw difficulty - there's much worse on the console, even if it's definitely the biggest contender for the hardest thing Nintendo themselves have ever put out - but that it's actively, delibrately unfair and cruel, then rubs your face in it.

The backwards warp zones are the most infamous, but there's also straight up kaizo blocks in this before kaizo was even a thing, some super blatant and obnoxious blind jumps, posion mushrooms in levels where the palette makes them hard to tell apart from the normal ones, and pipes that take you to all sorts of weird bullshit places. It gets to the point where the game actively discourages exploration and secret hunting, which is definitely what many would call a "choice".

Some of the novelty factor here is definitely gone with the advent of rom hacks and even Nintendo's own Mario Maker making levels that make even the most horseshit parts of this game look like a breeze, but it's a fascinating bit of Nintendo history none the less. I do honestly like this game, even if that's maybe the masochism talking,