Alright, I'll give some thoughts; I still haven't finished it yet, but I'll elaborate on that further that down.
Tunnel Putzl—Absolutely brilliant level throughout. It was so higly enjoyable to play through. Every time I've entered a new door, I was begging for it to not be over. The puzzles, the variety of ideas, and the different challenges kept me engaged throughout. So far, my favorite level of the pack. The best part was the pacing; as soon as I found the last bridge puzzle, I was thinking, 'Welp, I hope that was the last one, because I feel a bit burned out,' and the new section was something else entirely. Really kind of level I like making, and this one really sits well with me.
Tunnel Cranmore—Not enough cranberries, dagnabbit.
Maze of Madness—When I saw the title, I was terrified it was going to be tedious and a slog to get through. Surprisingly, it was quite the opposite. Good design; it felt both linear and open at the same time. It felt so big that as I was progressing, I got terrified of the idea that I would reach a dead end and it would require me to backtrack all the way back. But that wasn't the case. Maybe I got lucky and found the gems at the right moment, but if that's the case, it's obviously well thought out as well as it has good player guidance; I never felt I got lost or didn't know where I was. There was even optional candy behind gem doors, which you don't see very often; also, another idea I really like.
Tunnel Aqaxz—This one started so well. I was already thinking, we've got another top-tier level right there. Especially, I personally like difficult sections and multiple hazards, enemies, and lasers shooting you at the same time, so there was that at the beginning, and I was hyped. Then, there was the bridge puzzle, which was also very nice. The part with poles and rotating whatchyamaycallit hazards was good, but I think it went for too long. The one thing I don't quite understand in this level is the last part.
The part I don't understand:
The last door. So, when I encountered that door for the first time, I quickly made a note in my brain: okay, so this is obviously a door designed to get me back to the conclusion of the level when I switch that bridge over there. Got it. Now, maybe I've missed something or maybe there was some clever twist I didn't see, but that was not the case. You reach the end, open the yellow door, return back to the hall, and the bridge that you're supposed to jump through is now blocked. I don't like that at all. It's like trolling the player and saying, 'Welp, guess you'll have to backtrack, buddy.' I am sure that this was not the intent, but it sounds a bit mean spirited. I did find the secret, and it revealed who designed it, which also cut back on some backtracking, but everything besides that part was very highly enjoyable. The last bit, nope. But then again, maybe I've missed some clue or something, so I apologize if I sound frustrated, but that was my experience anyway.
Now for the reason I didn't finish this in one sitting…
Armageddon Fortress
Now it started out fine, but it began adding things that I feel are there just to troll the player, or maybe for the fun of it? The
amazing single goplat that does endless circles around, and you have to watch it and wait for it so long, and then jump on it and watch Keen ride that same goplat for way longer than it needs to be. And there were these massive halls with goplats, which I do get the appeal in making, but as a player, I do not see or know how big this massive hall is, and I am not motivated to explore it, as jumping from these goplats usually results in my death.
And then there was the invisible floor part. First I got angry when I realized what you did, then I figured, 'Oh, the candy shows where you can land,' but there are problems with this idea. If I want to explore this area and collect this candy, how could I remember where these floors are if there is no more candy to show my safe passage? And not only that, I think it requires you to backtrack through that hall because you need to place a bunch of gems there and return to the right to progress.
And then on top of all that, these tiles are solids. Meaning I oftentimes bump my head into nothingness and fall into my death. These just feel like trial and error; even though the idea wasn't all that bad, I don't like the execution of it.
And later on I got to the switch next to the Spindred staircase, and I am unsure whether you're expecting me to ride that goplat back up and hope to god that I can jump back through those openings between the spinny hazards all the while pressing down and not being able to see where I am supposed to jump. This is where I got overwhelmed and decided to pause for today, anyway.
I am sorry if I don't sound too harsh or discouraging. I am just being honest, and if I sound bitter, it's mostly just this last part that annoyed the hell out of me.
And, some errors/probles I've stumbled into:
You can get stuck in here:
Moved through the door tiles:

"I don’t care what model it was! No vacuum cleaner should give a human being a double polaroid!"