Games are generally a lot easier than they used to be, so I’m guessing most of today’s answers will come from older titles. What game have you played that had a level so difficult, you remember it to this day?
I have a few options on the table, the primary one being the Water Temple from Ocarina of Time, seen here. It frustrated me so much, I actually quit the game, as no, as a result, I have never beaten the game in its entirety. Yes, I could probably go back and do it now, as I’m smarter than I was at eleven, but this level stills scares me to this day.
Other examples would include rings levels from both Superman 64 (I’ve heard I’m not the only one who had problems with this), and also rings in GTA: San Andreas, where somehow flight school became the hardest damn mission in the entire game.
Alright, those are the ones I can think of off the top of my head, what about you? A “level” can also be a boss or a segment as well.