Night rank

Sky Castle - Pleasant opening to the pack that won't pose many problems to experienced solvers.
Lems Are Playing Freeze Tag - Arman's first level is definitely trickier, mainly getting your head around slider mechanics - those pesky critters!
Christmas Tree Hunting - Mobiethian's hardest level so far; working out how to contain the crowd as well as have the pioneer go in both directions. It may actually be his hardest off the pack, although Rocky Road runs it close. Clever stuff!
Silent Night, Holy Night - Quite a long solve time for this one, which will become a recurring theme of Armani's levels! The hard part here is working out the correct use for a pretty limited skillset for such a large level.
Lighter Than a Snowflake - The one that originally caused me to give up on Armani's levels in the pack. Coming back to it 5 months later, it's not as hard as I remembred but still gave me quite a lot of trouble (I always struggle where gliders are involved too!). Working out what skills you are going to need at the end is key, as well as the optimal path to the gap in the fire at the top right of the level, plus where you need to use the cloner (logically, it can only be one place).
Uphill Sled Ride - Nice puzzle! The tricky bit with this one is getting only two lemmings to go over the top while the rest are contained, making use of a skill in transtion, so that one of the two that go over can fence back up to the crowd.
Rocky Road - One of Mobiethian's hardest levels in the pack for my money. Another really well-designed puzzle.
Lost and Found - Not Armani's toughest level but working out how to release the infinitely looping shimmier can be hard; not so much the how as the when!
Claustrophobia 2 - Appropriate title given how tight (time-wise) this level is. Even with absolute optimal skill deployment, you will still only have a second to spare at the end!
Happy New Year! - This jointly authored level is deceptively difficult, working out the only correct path (I assume) to victory! Took a bit of thinking out, this one - well played, guys!
All I Want For Christmas Is... - The first level in the pack to have me partially stumped. Definitely Armani's hardest level in the Night rank. Small hint acknowledged, the lightbulb moment was realizing that the lemming on the right side has to do pretty much everything.
Living in a Fairy Tale - Gorgeous tileset. I always love levels that utilize it and this one is no exception!
The Lem is Home Alone! - Another joint effort that required a pretty long solve time!
Night of the Christmas Crystals - What I call a slightly more arcade style level due to all the jumping around. Fun!
The Bear Necessities - Tough one. Aside from All I Want, probably the longest solve time of the rank. I don't think I backrouted it, but I did have a diggger to spare at the end.

Daytime rank

Walking Bearfoot in the Snow - This is the rank where we really start to see the genius of Armani's level design! In this one, the tactic of allowing the crucial pioneer to fall through the trap unharmed by having a sacrificial worker lemming take his place took a lot of spotting. I haven't seen trap response times used in quite this way before, but had a hunch they might, and also, there wasn't really anything left to try at this point; it's quite a restrictive level, in terms of skills.
Wake Up When It's Christmas - A rare open-ended level from Armani and a ton of fun to play through!
Do the Polar Plunge - Not too hard, but also lots of fun - love jumpers!
Angels We Have Heard On High - An uncharacteristically easy joint level, but I suppose it's early in the rank. Very enjoyable nonetheless.
Your Gifts Are Over There - Neat idea to have the pioneer do his work underneath the crowd.
Skating on Thin Ice - Tricky one, but once you realize you can't use the digger at the start because you'll need him later and that the snowmen have climbable sides (not a sentence I ever expected to write!), the rest is straightforward.
Fluffy Snow Vs Rock Hard - Very clever, Armani, very clever.
Amphibious Operations - Difficult one for me as I always struggle a bit with the mechanics of swimmers but ultimately another nicely designed level from Armani!
Sky Shield - The hardest level of the pack so far, to my mind. Very, very long solve time. Though I got 95% of the way through I did need that final push from Armani to get me to see one little thing right at the end. Once again, a brilliantly designed level that utilizes every last skill.
Roller Coaster Mountain - In which we see once again that Mobiethian is a big fan of the lone pioneer, leading from the front!
Mele Kalikimaka - Tropical Christmas Vacation? I love the atmosphere of this one, nice break from the rest of the pack!
Like a Snowman Inside a Fridge - Another surprisingly straightforward joint effort but looks great and is fun to play through. Love this tileset too, it always reminds me of Festival Millas, which are among my favourite packs ever!
INside OUT - Strangely gave me a lot of trouble, given that it's not an especially hard level, but I was being especially dense. Looking at it afresh on a new day, it was quite obvious what needed to be done.
Watch Your Step! - Now we get to the business end of the pack in terms of Armani's levels. Long solve time. Very hard to work out what needs to be done. Clever use of the stoner to enable a single basher tunnel at the top. Clever use of sliders. Clever how it all comes together. Just a clever level.
The Lem is Lost in the City - Smart level design and again, it looks fantastic!
Warm Cozy Basement - One of Armani's hardest levels I would say. Very long solve time. Looks impossible at first, as Armani's levels often do. How to get that single floater to go back up and down to mine the tunnel to the crowd? A head-scratcher for sure! Lightbulb moment here was realizing that the blocker isn't for the crowd when they're at the top, but once they've got down, awaiting the miner to set them free. Genius level, honestly.
Constructus Interruptus - Arguably the hardest level of the pack or at least I think so, and Armani probably concurs. He was kind enough to say that I had almost solved it in a replay I sent him, but without the hint he gave, I doubt I would have finished it. The final bit I hadn't got is critical and as I said to him, I don't think I would've seen it in a month of Sundays! It's a 'trick' (more of a technique really) that I'll remember for future solving though. It's a clever level again and the clue's in the name, but travellers be warned - it's not easy in the slightest to work out what you're supposed to do!
Where Angels Dare - Another level that looked impossible at first pass, but in the end it wasn't too bad. Something of a breather level compared with the last two!
And They Lived Happily Ever After - All the neutrals drowning at the start made me laugh out loud! Had a platformer to spare at the end and a ton of jumpers. Is this a reference to being given an abundance of knitwear by relatives for Christmas, or am I reading too much into there?

Eon 1 - Be Attitude For Save One Nice level to start off the pack even if I got this one super quick. I love the part with bombing the second climber in order to make a turnaround point for the first one who needs to be interrupted with a builder after bashing and making a route to the exit.

Eon 2 - Trust Your Lucky Star? Not a hard level if not concerned with the talisman, but as mentioned it's super frustrating if going for it. A lot of the time the climber came at the wrong time and hence wouldn't be able to make it to the very top. Consider easing the talisman to make it less frustrating. It is a nice one though!

Eon 3 - I Am E.Z.T Nothing hard here other than you need to make sure you don't destroy all of the overhang on the far right edge, since that serves as a splatform for the Lemming trapped on the left side. It still took me longer than it should had. Not sure why it took me a while to figure it out

Eon 4 - Head Bang Bump Wash Dry Turn Blow Another one that I struggled with much longer than expected. Not sure why building to get over the teleporter from the right side took me a long time to figure out. This makes a big difference in that it allows the long basher to get to the receiver area in time to allow a neutral through after parking with a blocker and bombing to release one at the right time

Eon 5 - Four Shruggers Easy one just like Eon 1. The only hard part is the top Lemming using one builder only as delay, but it's not too hard to see after one spots catching the bottom climber with the middle Lemming by building and you see that attempting to build past the traps results in splatting after it's done. 

Neo 1 - One Hot Minute Wow, very nice talisman and one that took me a long time to figure out. It took a while for me to find a different way than having one climb to go on ahead before I succeeded. It really should had occurred to me that you will always fail the talisman if even one obstacle is climbed, but I didn't catch on apparently! As mentioned, the talisman solution is very well-hidden. Didn't think to use a digger to turn around instead of two bombers at the start. In this way, you will have all bombers to clear all the obstacles ahead so that no climbing is necessary, since it's impossible to achieve the talisman that way, even if you squeeze out the maximum potential in saving as much time as possible. Excellent talisman!

Neo 2 - So Many Spikes Somewhat hard and one in which you will always fail if you take the normal route of passing through the traps at the top, as all Lemmings get killed, even if you bomb the athlete to release the blocker so that he's compressed with the rest of the crowd and hence only 1 dies to each trap. It's not clear that a bomber is enough to not get anyone killed to the needles trap at the start. Nice solution with bombing close to the steel wall at the bottom so that the athlete is the one who goes to the exit!

Neo 3 - Eroded Ark Nice builderless level! These tend to be my favorite type of level in the game. Took me some time to see that the climber is the one who goes to the exit, not the floater. The floater simply prepares the route for the climber. Once you realize that, you have to figure out how to delay the others long enough to be able to send a climber at the right time but not so long that one of the diggers digs to the bottomless pit.

Neo 4 - Tower of Sacrifice Nice level by Icho here! Love the concept of the climbers needing to survive and go up the ramps to make turnaroud points by bombing. It can be a bit difficult to get the climbers to be first to get up the "tower of sacrifice" though. I'm guessing the floaters are for that purpose of making the timing easier, especially to release the Lemming trapped at the bottom by making him climb.

Neo 5 - The 6" Escape Plan Yea, sorry, this also made me rage. I really would suggest expanding and making more room available so that it isn't so tight on the execution. Remember, demanding precision to increase the difficulty is not a great way to do so, especially on an engine that emphasizes that the difficulty should come from the puzzle, not the execution It also wouldn't hurt to make some things more obvious that they wouldn't work, such as destroying the terrain before the exit being off by a few pixels and similarly with making it more obvious that the miner would fall past the exit at the top.   

One 1 - Umbrella Irony Irony indeed, as for some time I assigned the final floater to the wrong Lemming. That's simply due to me being so fixated on building on the far right with the second builder to turn around, when in fact you can just build on top of the green emerald in the middle of the level to do so. Doing this gets around the problem of the timing not working out in the middle of the level with the gap before the emerald. Excellent level!

One 2 - Aquarium Deception Wow, this is one of the most creative levels I've seen that involves the nuke! I should had picked up sooner that the nuke is involved due to the high Lemming count, combined with the very low save requirement, and how if you attempt to build over the gaps on both sides you'll always be a builder short. My only point of criticism here is that if my solution is intended, I would lower the terrain at the top so that it's clearer they won't walk out the top of the level and die. I'm not sure if the solution can be adapted to get to the exit from the right side instead.

One 3 - Clappy Clapple Backroute just like darkshoxx, though I haven't seen their solution yet. Mine's definitely one since I saved way more than 1 Lemming here

One 4 - Clues Do Easy one but only because I'm already aware of the double builder turnaround trick. Still, I like how every Lemming needs to keep moving forward in the level, especially as only the non-climber can make it to the exit. Well done!

One 5 - Blues Possibly the hardest level in the entire pack, I had a suspicion the nuke is involved here too. It just took me a while to figure out how to make it work, as it's way less obvious here than on One 2. Should had been clear due to always being a destructive skill short if taking some kind of normal route. All the cracks and everything in the level all seem to be due to backroute fixes and hence that kind of compromises the aesthetics of the level to an extent Even then, what do I know, as I haven't made that much levels in the Fire tileset yet. Nice solution but can be very hard to execute. That took me several tries before something finally worked, since I would be able to get the crowd to the exit but none would be able to exit since some explode to take away the terrain burying the trigger and hence the ones that stop on top of the exit trigger fall past it and therefore can't exit. The solution definitely reminds me of one of my levels for my upcoming Lemmings Memories pack, but as mentioned I'm not going to spoil which one it is You'll have to wait for me to release the pack first, if and when I ever do Even then, there's a possibility that people might have figured out which one if observant enough

One 6 - Bonus Level : The Blue Pi Nice level to finish the pack on but can still take several tries before something works as well. Here I managed to save a digger but should still be acceptable since it should only be possible to save just one Lemming. Looks like I'm not quite right in that it doesn't have to be the athlete that makes it to the exit. Any of the others can do too, as long as the floating block is used to get to it.