OK, so back in the day, I played craptons of games on my Commodore 64. One that used to just drive me nuts was Aliens.
I eventually got decent at it, but it took forever and a day to get past the first level, which was the spaceship re-entry procedure. You had to maneuver through a series of rings that, I assume, represented the safest trajectory for your ship through atmospheric re-entry.
At first it seems pretty easy, but once you run into turbulence, the rings are farther apart, and more scattered. Miss a ring, and you're pretty much screwed because you'll have to start over from the beginning.
This particular gameplay "feature" would come back to bite me in the ass with Superman 64, a game that I actually asked for. On purpose.
How bad is it? Ask the Angry Video Game Nerd. He pretty much says it all. But if you doubt his opinion, try looking up "Superman 64 sucks" on Google.