I played Super Metroid before NES Metroid and found Super Metroid much harder and took me much longer. I realize this isn’t too interesting but its funny that you had such an opposing experience to mine. It might have something to do with that I drew my own maps so I didnt have much trouble navigating, grinding to get health back at those pipes, and finding the patterns that usually held items. Also the combat, especially the bosses, were much harder in Super. In Metroid 1 you only had to spam missiles to win on kraid and ridley, and I didn’t die once until Mother Brain. Metroid 1 took more thought with all the cartography and well hidden secrets but I think Super was much more mechanically difficult.
It’s not my experience. It’s everyone’s experience. Everyone knows that Metroid 1 is much tougher than Super Metroid.
You should replay Super Metroid again. There are no ‘mechanically challenging’ bosses in Super Metroid. With all of them, you just jump up and shoot as many missiles as possible. One of them you just grapple beam the side of the level, and it is instant-death for boss. Even the metroids in Super Metroid are depressingly easy.
The truth as to why Super Metroid became popular over time is because the game is so ridiculously easy that the non-old school gamers can play it. I rented Super Metroid and finished it in a weekend. I couldn’t do that with Metroid. I’ve always considered Super Metroid to be the Kiddie Metroid.
Maybe it was due to the three dimensions, but I saw Metroid Prime as much more challenging than Super Metroid.