Bonus 1 : Hardest level of the pack for me, what a tough one to start the rank. I must say I cheated a little for this one, because while trying to solve the previous issue I had on Bonus 6, I saw a screenshot of a video by Swerdis which shows the position of the first blocker in this bonus 1. I did not think at all to set this blocker here, and it lead me to the solution.
It is another case of "assign the skill that will free the blocker before the blocker is even set", always hard to see for me.
Also my solution does not use the two upper pickups. For a long time I tried to catch them, but ended one lemming short of requirement, and this was because getting the two upper pickups used 1 climber and 1 builder, made me gain 1 climber and 1 builder, but loose the lemming ! So yeah, do not get those pickups and you're done. Intended ?

Bonus 2 : Better love sliders to play this one ! I could make a structure at the beginning to sort the swimmers and sliders directly, and another structure at the end to make them all go to their respective exit.
In the end I think my solution is quite clean, and I have one stacker and a couple of shimmier left. Maybe this was not intended ?

Bonus 3 : I could clear it with almost extensive study of all the possibilities here. Just save destructive at all cost.

Bonus 4 : Once you realize you only need 1 swimmer to cover the whole water needs, the level becomes easier ! Typical Armani stuff with the new skills : cloner a constructive lem, make a stoner at the most improbable place, have fun with gliders.

Bonus 5 : Easiest of the Bonus rank, may have been in the previous ones. At first I could not solve it because I was a bit frustrated by the others before and was searching for complicated stuff. This is a very regular level with a nice touch : assign the climber at the correct time.

Bonus 6 : Weirdly enough, this was a quick clear for me after the "hatch above the water??" issue was resolved by kaywhyn some posts earlier. The use of the cloner and builder is quite clear, getting a glider to shimmy all the way up is a bit tricky but nothing undoable if you've played some Armani before. Weircly enough, the hardest part for me was to time the fencer correctly so that the crowd would stay compact and go to the exit quickly enough.
But then saving the last glider was the thing : when you're out of everything, and playing the last level of a pack, what should you do ? I could find this fast enough because I had nothing else to do, and also because I recently played a kaywhyn's level in contest 33 that uses about the same trick : neutralize a lem for some frames with a oh-no animation.

Bonus 1 : So many difficult part in this level that I have no idea where to start :
*) compress to go the middle way with the crowd ? But I have no idea how to compress without loosing to many skills and lems, and I still have the issue of that bottom teleporter that will kill one more...
*) let the crowd use the upper teleporter ? Cannot do that either yet, getting there with the crowd uses a builder which I have to use elsewhere.
*) what about those pickups ? The top one is a builder, and I need to use a builder to get it, so nothing won here. Well actually I can win a climber in the process, but I dont know what to do with it...

Bonus 2. What I have to do is quite clear : forge a path for both the swimmer and sliders to reach the exit. I have decided that swimmers have to go right part, and sliders left part (maybe I'm wrong ?). But then my main difficulties are :
*) very beginning : I'd like to separate sliders and swimmers here but the only way I find to do this already uses 3 builders and 1 stacker. Too much for the rest of the level
*) avoid the splat on the right part with the swimmers. This uses so many builders that I am stuck after.
*) ending part where I have to turn the sliders around. Doable with a stacker, but then the swimmers cannot go to their own exit.

Bonus 4. Counting the gaps, I see that the skillset is one platformer short. So I need to set the stoner in the middle of the 2-platforms-long gap, and to clone the platformer here, great idea (hope I get it right).
I see where/how I have to set the stoner and how to reach it with a glider. But my issue is that to achieve this I need 2 swimmers, which means I need to use the cloner earlier, so no cloner left... Cannot overcome that.

Bonus 5. Does not seem so hard at first sight, but if I set the climber too early the I use too much ressources to avoid him dying at those climb=death part. I need that climber at both the beginning and at the end of the level, so no idea how to do that.
Also I cannot see how to use the bottom part of the level. Once I'm stuck in here, I have no idea how to get out since I have no destructive skill left...

Bonus 6. Not tried yet.

Retro 1 I did not read/follow the advice title to isolate the last lemming as a worker ! Instead I isolated him with good ol' break your own bridge technique. In the end I have just enough builders to clear.

Retro 2 I tried the 100% here, and had to time carefully the miners to do so. Doable, and some skills left.

Retro 3 That was pretty straightforward, as I am now used to making climbers turn around in miner/basher tunnels. Though at some point I was scared because I thought the climber could also escape to the left, but he can not !

Retro 4 Lead the way with bashers and contain crowd with miners.

Retro 5 Some tricks required but it works in the end. I wondered if 100% was doable, but saving a blocker looking the wrong direction way and standing above a bottomless pit looked too hard to me...

Retro 6 Not a hard level for once. The pickups and layout dictate quite clearly what has to be done. I love the fact that no matter which way the crowd exits the digger pit, one exit is there for them

Retro 7 Now this is masterfully designed, and the clues on where to place the blockers were very welcome ! Thank you Armani.

Retro 8 My first tentative were one basher short as I needed 3. But then by placing the 2 digger pits close to each other, the miner can act as mine+bash, so it works !

Retro 9 Weirdly enough, this one was a quick solve to me ! I saw the solution where the workers have to commit suicide to clear the way quite fast. Maybe my brain was trained after the first 8 levels and I was on Armani's wavelength like JawaJuice would say

Retro 10 This one took some time as possibilities are very large here. In the end I did not use the leftmost part of the level because it used the miner that I could not afford to loose for the rightmost part.
In order to reach the exit with the 2 left entrances, I had to bounce builders on a single blocker, twice but not at the same height. First time I see this in a level, nice idea if this is intended.

Retro 11 For a long time I did not know how to free that top-left blocker without making the crowd splat. Then I used a trick that is also used in the level ONE 4 Falling Steps of my Save One pack : mine a bridge so that lemmings can descend it but not ascend it.
This way I both free the crowd from the splat, and free the blocker with a single miner. Setting this up in this level requires some trials and errors and pixel precise placements of the blocker, last builder and miner though. Not usual as per Armani standard.

Reading other's solution I think this was not intended as people isolate the 4 needed workers with a blocker sooner, then use a trick to turn the miner around.
I think my solution is acceptable too, and remember that Armani was one of the few, if not the only, player who found this method in ONE 4 

Retro 12 Gosh this one was hard ! For a long time I had all pieces to solve this level, but could not set them up properly due to timing : mine too soon and everyone will splat, or bash too soon and you cannot mine later.
The idea to mine seemingly for nothing is just brilliant : mine for nothing but save a brdige, then use the bridge later to make the mine useful. Wow 

Avant-Garde 1 Back to lower difficulty with the start of this new rank, nothing much to say here. Great and doable level for newcomers, Armani can create them too !

Avant-Garde 2 I had fun toying around with the new skills in this weird design, makes me wonder what namida's room actually looks like 

Avant-Garde 3 Still in the doable difficulty, walkers are that strong.

Avant-Garde 4 Nice level where some lemmings have to take one route, and the others another route. Thanks again for the marks on the ground to place the laserers !

Avant-Garde 5 It starts to get tricky here : one miner for 2 tasks.

Avant-Garde 6 Extension, extension, extension. Good level, you'll definitely struggle without extensions.

Avant-Garde 7 Very good level, and taught me the wall-to-wall slider/jumper (Super Mario can do it with no particular skill in recent entries in the series !). Thank you for this because it will be used often later !

Avant-Garde 8 Zombies have to be led here, but dont touch them ! Walker is strong, did I say that already ? Also you have to manage builders correctly here : I kept on trying to make the water pits crossable in both ways, but it just wastes builders.

Avant-Garde 9 The Sled was a really difficult level to me, mainly because it looks like I'm not that good with gliders.
I spent a lot of time deciding how to escape the worker at the beginning, there are so many possibilities. But figuring how to extend the fencer was even harder. I used the stackers incorrectly and had to extend the fencer with 2 stackers only, which seems impossible here.
In the end I got a quite elegant solution, if I say so, where a single lemming can build the 3 necessary stacks by himself, thanks to a well placed stoner. I think this may be a bit backrouty because I have no use for the 3rd climber, and save one more than required ?

Avant-Garde 10 Now Armani shows his evil face : lead me to think I need the 3 provided stoners to fill that bottom gap 
But if you use all 3 here, then the level just does not work. Then count the pixel and use air-lem to make the work with only 2 stoners : brilliant idea !
It is worth noting that if you remove the first little gap to be filled and provide only 2 stoners, then the level will be easier bc player will have no choice but to fill the bottom gap with 2 stoners. I'm sure Armani thought about it and put that other gap as a bait. He's evil I told you.

Avant-Garde 11 Great zombie and jump/bounce everywhere level !
There are many ways to get up there within the (non existent ?!?) time-limit, but only one will work with the rest of the level.
Here I was stuck for a day or trying to figure how to free the crowd after getting rid of the zombie and forged the path to exit ; I always had a stacker left that I did not know where to use.
My error was a beginner one : think that a single worker has to do everything. Here, once the crazy bouncer has done his job, he can just exit peacefully and leave another worker from the crowd do the rest of the job. Nice touch.

Avant-Garde 12 Huuum, this level made me change my mind.
My mind before :
1) "pickups are not that great, their location and content give away too much of the solution of the level"
2) "unneeded pickups are just plain boring and bad design to try to fool the player"
My mind after Avant-Garde 12 Presents For You
1) "pickups may be fun and allow to create nice puzzle"
2) "unneeded pickups are necessary for point 1) to be true".
Here we have a great exemple where the unneeded pickups make the whole level good.
Solving the level was all about finding the most obvious and straightforward route for the worker up there to free the crowd, and make everything possible to try to stick to it, no matter which red-herrings pickups you leave behind. If you can do this successfully (and this involves using a cloner at the most improbable place of all), then the level is cleared in no time.
On the opposite, if you start thinking in terms of pickups first, try to get them all, or even focus a bit too much on them, then you wont be able to clear.
So yeah, if you remove the unneeded pickup, the level becomes too easy. It is also splendid that those unneeded pickups do not create unwanted solutions, but for that you can trust Armani and his secret weapon : give basher pickups in a level that does not need more bashers.

Avant-Garde 13 Thank you for the knid words. I remember 2021 to be a weird and rather bad year, as 2020 was before. But hey, now we're over it, have more kids (congrats on your again !) and life continues. So you were right.