The old MCZ2 was love-hate... people either liked it due to its solid layout, or hated it due to its difficulty and less than obvious gimmicks. This one wasn't as great as the old one in my opinion, but because it was generally easier and had gimmicks that are easy to recognize across the board, there were fewer low scores to drop the average.
What I'd like to see with the new one would be (again) a return of the old visual style with the new cave textures merely supporting them rather than being the level's main appearance.
One thing I also felt was missing in what I played of the new one was a sense of direction. While I didn't exactly get lost, the old one felt a little more progressive as it went from volcanic themes to factory themes. The lava shaft is one feature in particular I miss.
Also, you have some interesting gimmicks here, but most of them were only really fun the first time around. Try to use the falling rocks and pulleys in more imaginitive ways, maybe start bringing in more of the mechanical aspect of the level later on.
Your things really need some cleanup, the overlapping sfx really gives this away from the very beginning. Try to use hazards as methodically as possible so that the placement of a flamethrower doesn't feel random or the player doesn't ask himself why he's crossing another pointless area with falling rocks again.
Lastly, the button room felt somewhat pointless. First, don't hide the button. Second, there needs to be a purpose for pressing the button whether it is in gameplay or behind the scenes. Maybe put it in a niche behind some flamethrowers or something.
Overall, I really liked the level, but it could use plenty of improvement. Do note that just because there are a ton of awesome new textures doesn't mean that the old ones are off-limits or that you shouldn't try to make your own. (although, I will probably go on a mad rampage if half the contest maps start using MMx again like they used to...)