This is actually a neat level. Pretty much the entire level was well designed except for the part that Turtwig mentioned: when I made it there, I didn't have a leaf, so I could only break the brick by backtracking and tossing a Buzzy Beetle shell at it
Yay for unintentional alliteration!. In other words, if the player doesn't have a leaf and also killed all of the shelled enemies in that section, the level becomes impossible to beat, and I'd say that this is a bigger problem than the player off-screening the Key's layer or losing the key. I recommend removing the invisible blocks from that area (as well as the Goomba and Key layers) and putting the key inside the block. Plus, to prevent the player from being able to drop the key off-screen, you could add a floor to the water tunnel in between the key and the key-wall.
Also, why isn't there a warp leading back the way warp 9 (the one leading from Section 4 to Section 5) came from so that if the player goes into said warp and realizes he/she missed a secret, he/she can go back and get it?
On another note, the Koopa Klown Kar section was okay, but it did seem to overstay its welcome. Plus, there's no challenge to collecting the red coins since they're all in plain view and easily collectible. Regarding the sign, it's nice that you warn the player not to enter the pipe if he/she is still trying to get all of the red coins, but it could probably be implemented better so that Turtwig doesn't get confused. I don't have any suggestions for this, unfortunately.
Like I wrote earlier, pretty much everything else about the level is well designed. It was nice that you prevented the third SMW star's death event from being permanent and messing up the rest of the level. I especially liked what you did with the waterfall in Section 8; it almost looks 3D. In fact, regarding the graphics, this is the only flaw I found:
Summary:
GOOD:
-Graphic choices aren't terrible.
-Music fits the level well.
-Level design is well done for the most part.
-NPC placement is okay.
BAD:
-That whole brick debacle.
-Red coin challenge wasn't the least bit challenging. It might as well not be there.
-Warp 9 doesn't allow backtracking.
-Background/foreground inconsistency.
In conclusion: although that whole debacle with the player having to destroy the brick is a relatively major problem, the rest of the level is good enough that this is still an enjoyable level. I'd say this deserves a 6/10.
P.S. Your songs aren't properly labeled (and by that I mean Googling their names doesn't bring me to their source), and they don't have composer or album credits, either. Remember: music is just as important to levels as custom graphics, so be sure to cite where they're from. I was able to find out that alienjamyes is definitely from Frogatto; are all of the songs from Frogatto?
