So I just got to the part where you get Link and here are my thoughts so far:
-The story is dumb. Really dumb. I'm trying my best to ignore it and it's quickly gotten hindering enough to make me skip through it completely.
-There are massive difficulty spikes at random. Some puzzles right in the middle of a set are extremely hard because they're very precise about their timing. This is something I especially noticed in the lava and castle worlds. (screw "make poison mushroom die" puzzles in particular)
-That said, some of the puzzles are really clever and I found myself bamboozled by their traps quite a bit after I thought I had the solution.
-THAT said, a lot of the puzzles suffer from extreme visual clutter which makes it hard to see what's going on without examining the screen for a few minutes. The traps I fell into were often caused by missing a tiny detail in the scene which didn't stand out as important because everything looks largely the same in most levels.
-In addition to that, some levels feature red herrings. These red herrings don't make a puzzle more difficult, they just add to the clutter. I don't like them. Example:

The solution to this puzzle is to hit the red switch, kick the shell past the blue blocks and hit the red switch again. There is no need to ever press the blue switch in this level.
-The correct solutions for a lot of levels is very obscure. Sometimes it's so obscure that I start thinking my solution is cheese but way easier to execute than what is expected of me. This, again, is caused by clutter and everything looking the same.
-I hate the onJump gimmick. onJump is janky and nobody uses it ever for exactly that reason. Most of the puzzles could've worked if you coded a proper jump detection system, and all of them would've felt much better if you did.
-I love the first Waluigi boss it's really nice.
-Some levels can be cheesed. A lot. I beat this one (not this run but the one after) with 40 seconds left on the clock by lowering the donut block without collecting the coin. It works because a coin hitbox has a width of 28 while the donut block has 32:

I also chucked the mushroom block up there without hitting the switch. Good job, me!
-Literally every tutorial in this episode could've been done better. Considering this is a sequel AND an episode targeting a specific portion of the userbase (people who play puzzles) I don't think you have to introduce the concept of grabbing items or slashing as link. More obscure stuff like green arrows indicating level wrap or phantos just fucking you up completely is fine, though, as it's not part of the regular lineup of abilities.
-Speaking of arrows, I like how you put direction arrows over skull rafts to indicate their direction. I hate that you stopped doing that after just a few levels. It's inconsistent and weird.
-This toad is a liar:
-Probably my favourite puzzle in the entire game so far is this one:
It's not hard to figure out what you have to do, but its shape is deceiving and makes you think for a bit. Not about "what do I have to do", but rather "how am I gonna accomplish what I have to do". It's clear, easy to look at and was a lot of fun to execute.
-Screw item babysitting in most cases.
Will probably continue playing another day to see what else it has in store. Some concepts so far really surprised me while most levels were just a drag of carrying items around or hitting switches while trying to figure out what's asked of you.
I rate it with "fair" for now. Might change my vote later but don't count on it.