Rule2 All for 4 and 4 for all
I had quite a lot of leftover skills on this one. I like the idea of long platformer bridge at the middle so the shimmier lemming can keep going and push button. Otherwise, it's too expensive to push the button in the wall.
Rule3  Drown those Zombies!
I had quite a lot of leftover skills on this one too. I successfully drown all those zombies as the title say, but I think I'm still missing some core tricks.

Rule2 Let's Play Games!
This level was quite hard. The main difficulty of the level was that I had to save at least one lemming from the bottom. I don't know if these stacker/stoner things in my solutions are intended.
Rule3  Random Acts of Nastiness
This is my favourite level of today! I expect there's some very nice levels I haven't played in rule1, but this level is my highlight so far. How to save neutrals while distracting zombies at the same time was the main difficulty factor.

These levels showcase quite a lot of terrain pieces and objects of your new tileset! I especially love the pinball terrains, glitterling pink conveyor belt and slot machine object in casino level! Well, I actually tried to find something to complain about the tilesets, but almost nothing to point out. All the objects have their own animation so it's easy to tell what is terrain and what is object while making the tilesets dynamic. One thing(Let's Play Games!) : at first I expect the triangular terrain pieces at the bottom right are destructible terrains. They don't look steely enough I think, but it's my personal taste. So let's see what other people say about this.

Rule2 Lab Lesson: Bean Machine
At first I started the level and thought : I only need to push those two button with 2 jumpers and 2 gliders and the level is self solving after that. Is this level that easy? I kept striking time skip button, all the neutral splat, and I realized I had to prepare platforms to save the neutrals. I was a dumb. Anyway the level wasn't that hard but really creative. This is the first level I found the flipper is used in meaningful way.
Rule3 Trinity Of The Crypt
I was quite surprised that this level has very similar theme to my rule3 level. In my level, zombie disarmer is not a climber but the normal lemming and the neutral are climbers instead, but the main idea is same as yours. The level seemed very difficult at first glance but I think  it's sort of "go with the flow" level so it didn't take too much time to solve.

Rule2 Lemmings Touchdown in a Colorful World
Hehe, I found no-shmmier solution. I cloned the platformer so the cloned platformer turn around immediately so I could get two worker lemmings facing same direction. I guess the intended solution use shimmiers to push the buttons on the yellow and red square blocks maybe..?
Rule3 The Love-Hate Triangle
I didn't take advantage of zombie disarmer so this might be a backroute

Rule2 All Your Bees Are Belong to Us
Space and Honeycomb, very interesting combination actually. They seem to have no similarities at all but the level looks nice and aesthetically pleasant. Blue-yellow is complementary colors pair so this could be one of the reason I think.

Rule2 Purple Pit of Peril
Nice and easy level. I'm normally not a big fan of purple tileset level but this level looks nice.

Rule2  Lemminas im Kraftwerk
This level seemed a bit open ended so I tried to speedrun this level.(multitasking as hell ) The level provide quite a lot of skills but still challenging enough. Especially I had to quickly find the way to save the neutral walking toward the trap. And saving the lemminas surrounded by force field was qute tricky too. Nice job Willem over all

Rule3  Immortal
Wow, I didn't know that it's possible to place pre-assingned shimmier! Pre-assinged shimmier has definitely puzzle potential it seems. Sadly, I think my solution is a backroute. I have quite a lot of leftover skills.

Rule3 The Chamber of Mummies
I had very much fun playing this level! Well done Dullstar! I think there are many valid but equally challenging solutions to this levels.