It's been a while since I have posted an opinion topic; discuss the hardest video game challenge you've ever faced.
For me, it is one from Monkey Ball: Banana Blitz. Essentially, the game has you moving a monkey around in a ball to the goal. In one of the super secret levels, you're faced with a course that seems simple enough, simply a multicolored pathway with a couple of platforms to jump on then an incline to the goal. However, to my surprise and horror, those multicolors are actually varying levels of pyramid tiles, which are difficult to navigate and even harder to land on without going off the edge. In fact, the main way you fall off the edge in this one is jumping on the 6 platforms with these tiles onto the paths that also contain the tiles. As if this wasn't bad enough, the testers of the game forgot to test this level apparently, because a certain plain platform near the goal has a glitch where you actually fall through it as if it wasn't a platform. I would have probably won this level if it weren't for the glitch, so even though I haven't officially completed it yet, I consider it beaten, yet I still do not feel satisfied.