review:
I agree with Marina: the gimmick wasn't really implemented well. The smog obscures vision too much and is on screen too long for the player to be able to react to incoming obstacles. Even if you were going for a level where the player has to view his/her surroundings and dash forward while the smog prevents the generators from generating, the player would still need time to view his/her surroundings, meaning the smog needs to be made more transparent. If not, you should add another event so that the smog is only on screen for 2 seconds max.
On top of the smog, the level has its fair share of problems. For starters, it's unintuitive that the Hammer Bros have playerblocktop=1; either this should be changed, or the Hammer Bro's graphic should be changed to reflect this. Second, there's this:
The wall of Bullet Bills on the right is impossible to avoid if the player jumped off of the tank and missed the buried flame pipe (which isn't hard to believe because of the smog and since it isn't really indicated very well). I recommend moving the large Bullet Bill down by two units so the player can still make it past the wall without the flame pipe, without preempting it, or without taking a hit.

Lastly, the boss is just a generic SMB1 Bowser fight in a flat, empty room with the exception of a Hammer Bro at the top-left, which really doesn't make any difference. On top of being a lazy design choice, there's also no checkpoint in the level, so if the player dies at the boss, he/she is forced to go through the entire level again. You should add a checkpoint at the start of section 2 as well as try to redesign the room so that the boss isn't super generic. It doesn't even need to be super complicated or take much effort to make, as evidenced by my tutorial on SMBX's pre-programmed AIs:
http://www.supermariobrosx.org/forums/v ... =81&t=8890
Also, the reason the music is delayed before playing is because it has album art. If you put it into this converter, you'll get a plain MP3 file and it will play immediately:
http://audio.online-convert.com/convert-to-mp3
Summary:
GOOD:
-Graphics aren't terrible.
-Level/gimmick has potential.
BAD:
--SMOG ISN'T IMPLEMENTED WELL.
-playerblocktop=1 Hammer Bros.
-Bullet Bill beginner's trap.
--PRE-PROGRAMMED AI IN AN EMPTY ROOM (the Hammer Bro doesn't count, as previously stated).
--NO CHECKPOINT.
-Music doesn't really fit the level well. Sure, Panic Puppet Zone was very machine-oriented, but it also had a bright palette.
In conclusion: rather than just stick a gimmick on one of your older levels, you should also redesign said level around said gimmick so that they work with each other rather than against each other. I'd say this deserves a...3.5/10.