It’s funny, I generally hate hard games, but I’m very fond of Ghosts 'n Goblins (both the arcade and NES versions) and Super Ghouls 'n Ghosts due to playing them so much in my childhood.
I didn’t have a guide, but got stuck for days at the part where you have to super bomb the glass tube. I just did it out of desperation and couldn’t believe it worked! A similar thing happened 5 years earlier in Simon’s Quest when you have to hold crouch while holding the blue crystal. Come to think of it, Super Metroid might just be the last game in which I got stuck like that before I had access to the internet to look these things up.
I’m old and buy physical whenever possible so I can trade them in when I’m done. It will suck when console online stores have the monopoly - I might have to go PC Master Race when that happens (complete with eyepatch).