You could've at least sent one of us a PM-download at some point before, but whatever. Might as well see what you've got anyways...
EDIT: Okay, after trying your level... man, this was hard. And annoying on top of that. Half-hard, half annoying... and not in the most ideal way if you ask me.
For starts, there is a general issue with the first half of your level where sprites were often disappearing because you simply had too many sprites within the same area (or a Volacno Lotus spits out fireballs that cause things to despawn). For example, a springboard failed to spawn in the above screenshot.
I also noticed this level has a serious lack of powerups, with only two Mushrooms provided throughout the entire stage, one near the begining of the level, and the other at the checkpoint. I think this, above all else, is the major contributer to the difficulty here.
It also doesn't help that the first Mushroom disappears off the top of the screen when you reveal it--at first I thought: "Oh, no, no, no, you did NOT test this, did you?!"
...then about five seconds later it showed up behind me? Later attempts showed me it just stays up high for an usually long time, contrary to my knowledge of general Mario physics!
Nitpick: Glitched ON/OFF block sprite. Also, what is this thing even used for?
The Monty Moles that show up during the block snake run follow me down into this hole. While I could usually stomp the second one before the snake catches up, the first one is already running on munchers by the time it pops out, meaning he drops on my head afterwards unless I can react quickly.
Nitpick: Uh, Mario can suddenly stomp fireballs now? (Yes, I know they're just reskinned Cheep-cheeps).
Picture pretty much sums up my experience with this half.
This was where the level went from difficult to outright annoying. Here's the thing: I liked the idea
of your gimmick, but it's got a major flaw in that the "fake block boos" spend too much of their time disguised as blocks that I often found myself jumping into traps. Now some of you might be thinking "Well, you should've paid attention!" That may be, but care to explain what I was supposed to do when I was confronted with this?
I had no idea what to do here until the answer showed up too late. If I had seen those ghosts show themselves earlier, before I was dunked into the lava, I would've known exactly what was going on.
As for other issues?
Nitpick: Climbing up these ropes and platforms was surprisingly annoying as Big Mario, as I kept bumping my head into the ceilings, or slipping off the slope.
Hmmm, this looks interesting. I should check it out!
Woah, gotta think fast! Placing that kind of steep-slope terrain below a blind jump isn't exactly a nice thing to do to the player.
This setup was just horribly unfair...
Overall opinion: As to be expected from you, your level had great aesthetics. You also had clever ideas, but not the best implementation of them. A scarcity of powerups combined with lots of enemies makes for a rather harsh slog through the first half, while the ghost-effect on the fake blocks of the second half isn't always apparent when I'd want it to be. All of these could've easily been fixed, had you set aside a bit more time to work on your level and get testers, but I'm not even sure if we're allowed to make changes now that the deadline has passed.
My Let's Play channel
(Current LP: Final Fantasy VI, MegaMari)