No opening statement; I'm going straight to my review:
Well, this level was certainly difficult; I'll grant you that. However, there's a difference between challenging and unfair. Your level was unfair. Let me explain:
Your level is mainly one horizontal section, but most of the moving hazards consist of Podobos and Roto-Discs. The problem with that is that if the Podobos and/or Roto-Discs aren't
spawned at the correct time, the level
actually becomes impossible and there's nothing the player can do about it. Examples:

Bullet Bill Cannons have spawn time, too.

If you want to make a level that requires precision jumping, that's okay, but don't make it require precision spawning, because that only makes the level luck based. A good way to ensure that NPCs spawn at the correct time is to only use sections that are one screen, and link them with warps. Also, having an invisible block one unit beside a platform isn't challenging; it's cheap:
Finally, your midpoint is criminally imbalanced since your boss fight is leagues easier than anything else in the level. Seriously, I beat the boss on my first try in less than one minute. I recommend that you move the midpoint around where my first screenshot is (don't remove the shortcut at the beginning, though).
In conclusion:
I like a good challenge as much as the next person, but this challenge wasn't very good. I'd say this deserves a...5/10.
P.S. It's possible to get stuck here: