Jan '26 update : can you Save One Lemming ? (16 levels, medium-hard)

[Guigui]

Congrats on clearing ONE rank JawaJuice !

I did not have time to finish watching kaywhyn LP yet, and did not watch your solutions for ONE either. But from the comments alone I can say that the following :

ONE 2 Aquarium Deception backrouted by kaywhyn and JawaJuice. No nuke involved here. Solution is simpler and it did not occur to me that nuke was possible. You guys are crazy to even try this when the exit is so close to the hatch, you realize in 30 seconds that you dont have enough builders to go the long way, and most of all the level title tells you the Aquarium is a Deception

ONE 3 Clappy Clapple backrouted by kaywhyn and JawaJuice. My bad, backroute is obvious.

ONE 4 Clues Do backrouted by kaywhyn and JawaJuice. Compression of climbers not necessary, and kills the purpose of the level. I thought I had this covered, but you both beat me here.

ONE 5 Blues backrouted by at least JawaJuice. You're not supposed to save 3 here. Though it is funny to note that the core of the backroute solution you both gave for ONE 2 is the intended for ONE 5 !

ONE 6 The Blue Pi backrouted by kaywhyn. The athlete is the one that's supposed to go in, the way JawaJuice did. Then you can, as he said, sit back and enjoy your C.O.N.G.R.A.T.S


Now that this list is done comes the obvious conclusion : ONE rank needs yet another patch ! I should also apologize for presenting the rank as is, since it lead you to search solutions that are actually harder to pull off than what intended are, thus the frustration.

I'd say only ONE 5 may qualify as hard to execute bc it requires some precise timing at the end, though nothing as impossible as what you did in ONE 2 for instance.

So my next move is to make another update when time comes, then maybe release all intended solutions ? Not sure about that though, because I notice now that it is easier for people to find backroutes when they do not know intended, of course ! So I thank you for all being playtesters of the pack 

[JawaJuice]

Ah Guigui, I think I owe you an apology re: my comments on ONE 2, then

Spoiler

The nuke solution wasn't my absolute first idea actually that was to build over to the button on the left side, and inside the 'hatch room', build up through the ceiling to the hatch. However, this proved impossible as it takes a minimum of 8 builders to build up through the thin ceiling and a minimum of 8 to build over to the button, making for a total of 16, which you don't have! I also thought of building up through the ceiling in both directions, but again, ran out of builders!

Not surprised in the slightest that ONE 3 was a backroute!

I AM surprised ONE 4 was a backroute - that seemed like a pretty neat solution, if I do say so myself

Also kinda surprised ONE 5 is a backroute - I just couldn't see any other way of getting the crowd close to the exit, and believe me, I spent hours on this one lol!

kaywhyn probably deserves some kind of prize for backrouting ONE 6 - that's an impressive feat requiring insane precision!

Spoiler

Just curious, is 'This is not a Lemmings puzzle' a subtle reference to Magritte's Ceci n'est pas une pipe? XD

I'll look forward to your updated levels!

[Guigui]

Alright, now I finished watching carefully all the replays from you all, and the tremendous LP by kaywhyn.

I learned a lot from the replays, and have a very fun time watching kaywhyn playing my levels. Kaywhyn, it was a joy to hear your comments, to see you falling for most of the traps I set up and struggling on all the little details I put in there to avoid nasty backroutes

As already said, you and other players overcomplicated some stuffs, I'll most certainly write a PM to give some details and intended solutions on the most complicated stuff. Also, I need to defend my NEO 5 level, which both of you backrouted and dislkiked ! 

So now comes the time for a major revamp of the ONE rank, along with some levels in the other ranks. I'll be sure to post it here when it is done.

Finally, to honor the time and effort kaywhyn and JawaJuice put in solving some levels not the intended way  , I join those levels and their crazy replays.
Those solutions will not work on the newer version of the levels to come 

ONE 4 Clues Do and ONE 6 The Blue Pi here :

[Guigui]

ONE 2 Aquarium Deception and ONE 5 Blues here :

[JawaJuice]

What can I say? Having once stated on one of my early posts that I wasn't very good at discovering backroutes, I better change my slogan to 'If there's a backroute, I'll find it.' Just don't expect me to find your intended solution Honestly, I wouldn't even bother patching ONE 6 - no-one else would even attempt, let alone pull off, what kaywhyn did there!

[Guigui]

Just a little word to let players know that the Save One update is currently being worked on. I'll upload it when time comes, before 2026 hopefully.

I will also state here that I will (try to) not do that many updates in the future. It is quite hard for me to accept that some players do not go my own route, but I now understand that it is not necessary to change the levels each and every time this happens.

Thanks again to the players, and to the playtesters.

[Guigui]

After some weeks of tweaking, playtesting, kind words from JawaJuice, more tweaking, more playtesting, unparalleled backroute finder skills by kaywhyn, and more tweaking, I am happy to announce the Save One pack has been updated to its January 2026 version ! (Happy new year everyone btw)

You can find the updated pack in the original post of this thread, just unzip in your main NL folder.

Hopefully the pack is as less prone to not enjoyable backroutes as it can be. This has been a long way, and I send thanks again to everyone who participated in this update, either by playtesting or by sending replays earlier here.

Even though many levels layouts have changed in this update, I kept the original intended solutions. This means that if you had found the intended, you wont have trouble clearing a level whose replay has been broken by the update.
Still, I feel a bit bad about breaking so many replays. So I'm now making a list for all of you players to precise which levels have received significant changes, under spoiler after your respective quotes :

Just posting an update of my replay collection. 

Spoiler

You know all intended since beta test.
EON 2, NEO 2, NEO 5, ONE 2, ONE 3, ONE 4, ONE 6 layouts have changed but the same solution works.
ONE 5 changed more, the intended is still the same but requires precise assignment of skill to clear easily.

resolved updated levels 

Spoiler

EON 2, NEO 2, NEO 5, ONE 2, ONE 3, ONE 4, ONE 6 layouts have changed but the same solution works.

ONE 5 changed more, and I blocked your backroute. Maybe you'll have to change your strategy to Save One ? Or find another backroute ? (please dont!)

Solved the Eon levels ...

Spoiler

EON 2 has been modified to prevent your solution that made so little use of the crowd.

Be welcome if you want to try the other ranks. Though be aware that playtesters said that the level are not sorted by increasing difficulty, so do not hesistate to skip a level that feels too hard.

I have tried ** all the ** ranks, and here are the replays of my solutions.

Spoiler

EON 2 : changed the vertical structure that allowed the pioneer to get in by himself. Cooperation with the crowd is required

NEO 2 : prevented your crazy backroute that went through one of the spikes route, when the title itself says it should not happen. Still cannot believe that this solution worked !

NEO 5 : layout has changed but you had the intended solution

The whole ONE rank changed ! You were the first to bakcroute it almost completely, JawaJuice and kaywhyn came after you and you all gave me major work to achieve this update. Thank you.
Be welcome to try the ONE rank again if you like, hopefully you'll find new levels here.

"I'm in love with NEO 5 :p"

Spoiler

You know all intended solutions since your playtest, may have to replay some of them to get the green check.
Your alternate solution for ONE 4 is still possible, and kaywhyn found it instead of the intended during his playtest !

Current Work In progress

Spoiler

NEO 2 has changed to prevent your nasty backroute of bashing illegal terrain to remove a single pixel under your feet. Intended solution is harder to spot. This level may not be positionned correctly in the whole pack in terms of difficulty.

ONE 3 has also changed to block your backroute that saved more than one. Once again this level may not be at its correct place, too easy for the last rank.

Feel free to try other ranks/levels if you like. As you have seen, the difficulty curve is not consistent !

Now, after all this time spent with the Save One concept that came to me (and my 10yo kid!) when toying with the editor, I'll try to give a set of 3 rules describing what would be, in my opinion, a very solid Save One level :

Rule 1) The player should only be able to save 1 lemming.

Rule 2) The lemmings count should be at least 2, and the saved lemming should not be able to reach the exit by himself. In other words, there should be interaction of any kind between the saved lemming and the other(s).

Rule 3) Even if there were more lemmings coming out from the entrance (lets say 20% more lemmings for instance), the player should still not be able to save more than one lemming.


Rule 1) is obvious. Rule 2) is what differentiate the Save One pack from Dexter's Lock and Key pack. And Rule 3) is the cherry on the cake but very hard to fulfill actually.
In the Save One pack, all levels (hopefully) satisfy Rule 1) and Rule 2), but not all levels satisfy Rule 3) :
Levels that fulfill Rule 3) in the most satisfying way imo : EON 4, NEO 2, NEO 3, ONE 2, ONE 3, ONE 5.
Levels that fulfill Rule 3) but in a not interesting way : EON 2, NEO 5, ONE 1.
Levels that do not fullfil Rule 3) : EON 3, NEO 4 (sorry IchoTolot, I did not state the rule to you!), ONE 4.


Finally, I now want to make a vow to try not to update the pack as frequently as I did until now. I've been working a lot those past weeks to get the pack to its current state and I feel it now deserves to be left untouched for a while.
I'm not hiding it will be hard for me to see you players going unintended ways --maybe even breaking Rule 1) you devils!-- , but I now understand this is the actual game played by the level designer.
I should learn to feel happy by just knowing that you people play the levels and have fun with them, so keep them replays coming ! 

[JawaJuice]

Congrats on your latest release of Save One, @Guigui! It was fun to playtest!

I think you set yourself quite a hard task for your first pack; the nature of its strict rule set probably makes it more prone to backroutes than other packs would be. This was a very memorable and enjoyable pack overall, but maybe you'll make it a bit easier on yourself next time I look forward to your follow-up, whenever it comes along!

[kaywhyn]

Hello @Guigui,

I have resolved the latest updates, the Jan2026 one you posted almost a week ago. I have attached my entire replay collection with the new replays. Here, you just need to check Neo 2, One 2, One 3, and One 6. All these new ones look good now, so great job for finally getting Neo 2, One 2, and One 3 backroute-proof! For One 2, I'm not sure whether or not to praise that one, but that's only because there was so much trial and error I resorted to before I finally found something that works, especially the talisman. I can confirm I can no longer pull off any crazy nuke shenanigans on it which I've done for a few past versions you sent me for further testing So, with the thought that my solution has to be intended now, I checked your intended talisman solution and as I suspected, I really overcomplicated it! Of course, as you can clearly see I completely missed

Spoiler

the visual clue of the green terrain piece ledged in between the marble brick pieces for where to start the building! I was definitely wondering about that and I simply failed to figure out its meaning  

As for One 6, unfortunately, you'll going to hate me for that because I still managed to spare a digger I still haven't caught on to the riddle, and I'm definitely wondering if it's just from my lack of Back to the Future knowledge. As mentioned, I haven't seen any of the films fully

So, unless you feel like not fixing up One 6 anymore, I honestly am not sure if further fixes would just lead to a complete mess now

Now, after all this time spent with the Save One concept that came to me (and my 10yo kid!) when toying with the editor, I'll try to give a set of 3 rules describing what would be, in my opinion, a very solid Save One level :

Rule 1) The player should only be able to save 1 lemming.

Rule 2) The lemmings count should be at least 2, and the saved lemming should not be able to reach the exit by himself. In other words, there should be interaction of any kind between the saved lemming and the other(s).

Rule 3) Even if there were more lemmings coming out from the entrance (lets say 20% more lemmings for instance), the player should still not be able to save more than one lemming.


Rule 1) is obvious. Rule 2) is what differentiate the Save One pack from Dexter's Lock and Key pack. And Rule 3) is the cherry on the cake but very hard to fulfill actually.
In the Save One pack, all levels (hopefully) satisfy Rule 1) and Rule 2), but not all levels satisfy Rule 3) :
Levels that fulfill Rule 3) in the most satisfying way imo : EON 4, NEO 2, NEO 3, ONE 2, ONE 3, ONE 5.
Levels that fulfill Rule 3) but in a not interesting way : EON 2, NEO 5, ONE 1.
Levels that do not fullfil Rule 3) : EON 3, NEO 4 (sorry IchoTolot, I did not state the rule to you!), ONE 4.

I must say the concept/theme you were going for with this level pack is great! Sure, some level types are definitely far more prone to backroutes than others, but as with most things, they can be avoided with clever and careful level designing. That being said, I, along with some others who played your pack, totally didn't expect and was surprised to hear that practically the entire One rank was backrouted

I also mentioned one other time that backroutes will pretty much always happen no matter how long one has been making levels. I've been making levels for about 5 years now and I still haven't gotten that much better at backroute fixing since I first started back in 2021, though I think I've gotten somewhat better, especially with my more recent stuff. In fairness, it's likely due to my intended solutions being somewhat complicated Also, only seeing the intended way definitely leaves us designers blind to potential backroutes! I'm definitely hoping my upcoming Lemmings Memories level pack that's currently a work in progress won't be ripped apart so badly, but knowing myself I can probably expect a lot of backroutes in the first pass of pre-testing whenever that phase opens

Best of luck with GeoffLems! It's an excellent pack and one that's on the easier side than most other level packs!