This pack has now been converted to .rlv for RetroLemmini. Post here if you encounter any issues playing this pack, have any replays to share, or general comments/feedback.

Enjoy MazuLems!

MazuLems - originally by Martin Zurlinden, converted by ericderkovits.

Eric's conversion notes

ok, Here is Mazulems For Superlemmini. I got the levels from the Lemmings level database. Only had to do a few minor edits.

Mazulems is a small pack(30 levels + 2 extra levels) which uses the standard styles and the original 8 skills.

The levels use the standard Amiga lemmings music track except for levels 18 to 23 which use the ohno music track (to match NL's version thanks to Swerdis's Youtube play of the pack.)

Just extract the .rar to the main Superlemmini folder (will fall into place). There will be 3 folders(levels folder, music folder which has the ohno tracks for the 6 levels (the other amiga lemmings tracks should already be in the music folder so no need to include those), and a replays folder)

Now here is another great pack for Superlemmini. I've already started posting replays for the pack on my youtube channel.

I managed save 3 on Betcha can't save just one!, save 4 seems impossible. Do we want to edit levels to make 100% possible? I'm 50/50 on whether we should tbh.

The lists I posted are just there to document my favourites, really. Of course I'd like to see them included, but I'm equally happy to leave level selection entirely up to Proxima; I'll ultimately back whatever he decides upon, even if it means some of my picks don't make the cut. I also strongly support Mobius' picks as well.

Good work so far, everyone, keep it up!

Quote from: roltemurto on April 02, 2026, 07:34:31 AMOn your concern about existing lemming effects (countdowns, balloon pop, etc.) potentially rendering beneath the foreground object: for this use case that's actually acceptable or even preferable. A timebomb countdown visible through a tunnel arch would look fine and is arguably better than it being hidden.

My concern is the opposite: the lemming being behind the paint object, but the effect (countdown, portal warp, etc) being above the paint object. There would likely be a way to sort this out, though.

Quote from: roltemurto on April 02, 2026, 07:34:31 AM- Additionally, when a lemming's position is covered by a FOREGROUND-flagged decoration, you can have the engine draw a simple outline or silhouette of that lemming to rlEffects as well, ater the decoration is composited. Since both would write to the same layer and decorations are drawn before lemmings in the pipeline, the outline would naturally sit on top of the foreground asset. I believe the infrastructure for this already exists in the codebase as the CombineFixedColor is already used for similar fixed-color overlay passes and the lemming's bounding rect is readily available at draw time.

Hmm. A good solution to the 'hiding the lemmings' problem, but by no means trivial to implement and, considering that the proposed feature is intended to be purely visual, could spoil the intended aesthetic somewhat...?

Quote from: roltemurto on April 02, 2026, 07:34:31 AMAnd sincerely thank you for keeping "The" nostalgia alive and keep improving it up to this day. I was stunned with disbelief when I discovered your fork (and NeoLemmix to be totally frank).
I wish you a great day!

Thank you for your kind words, I'm glad you're enjoying SuperLemmix!

I should've known. Good one!

Quote from: kaywhyn on April 02, 2026, 08:44:41 AMYes, splitting the current v4.0 RotL pack into two packs of 120 levels each and then as a result Lemmings Assemble is its own thing independent of any of the RotL packs (save for any levels that get used from the Outtakes and overflow/extra pool) available makes complete sense to me now.
...
I agree about not leaving the 2022 RotL pack the way it currently is

Glad to know. It's important that we all want the same thing here, and we seem to (which is great!)

Quote from: kaywhyn on April 02, 2026, 08:44:41 AMI don't think it'll be possible to fix all backroutes with only one update ... Here, I would suggest giving it maybe 3 versions, similar to how you detailed me your approach to backroute fixing your levels

Absolutely, that's reasonable.

The only thing I'd suggest is that perhaps rather than a fixed number limit, it may be best to set a deadline after which "no more fixes" is put in place (similar to namida's approach with NL). That might be more appropriate for this particular project, and means that you can revise levels as many times as you see fit up until that date.

It's ultimately up to you how you want to approach this, though. Whatever you think is best.

Quote from: kaywhyn on April 02, 2026, 08:44:41 AMOne thing, and that is I would suggest letting the poll run its course first before we commit to our duties.

Agreed, with the exception of Proxima drafting the first pack. It's a good way to get the ball rolling, and is unlikely to be impacted too much by the votes anyway.

Quote from: Proxima on April 03, 2026, 10:27:35 AMmy hope is that by putting in the work now, we'll reach a version we're happy to sign off on as the definitive final version so that no long-term maintenance is necessary (especially as the NL engine will now have no further updates). If more backroutes turn up later, we just accept that the pack isn't perfect.

Strongly, strongly agree.

Whatever kaywhyn decides as regards to backroute-fix limits, it seems to be clear to all of us that there should be a limit, and that limit shouldn't be surpassed, at least not by any of us.

One of the main purposes of this project is to have a set-and-forget couple of packs which don't need endless maintenance, and then a new pack to which we can add levels going forward.

Quote from: Proxima on April 03, 2026, 10:27:35 AMI'd like it to be done so that I can move on and get back to finishing my own pack (which I have been promising to do for years at this point).

Can't wait!

Quote from: WillLem on April 03, 2026, 11:28:22 PMJust to add my own two cents to this, here are my favourite levels so far (which I'd be sad to see removed unless they're present in another pack somewhere):

NOTE: I'll update these lists later as I'm still working my way through the pack - when I do update them, I'll repost the lists for convenience.

WillLem's favourite ROTL levels

Rounds and swingabouts
Bat country
No loitering
Crystal caves
Lem dunk (a save all solution would be nice)
Brick City
Crossing The Chasm
Harder, Better, Miner, Stronger
Don't Leave Me Hanging!
Lempire State Building
Use the grey matter for this one
Think Again!
Betcha can't save just one! (a save all solution should be possible, though)
Fiery Depths
The Climbing Frame
A break in the pillar
Dilemma

And, some that I've identified as possible levels to remove:

Candidates for removal

Build it up with iron and steel - far too pixel-precise, at least in the RL version. If kept, it should be revised to allow more margin for error
Subterranean - this one look fairly ugly due to what I can only imagine are backroute-fixes which pretty much give away the solution. I'd suggest revising the backroute fixes or removing the level
Crossing Paths Part Two - not as interesting as part one, and easier. The two could swap places!

Also, I voted for "keep them in the level pool". Reason: there seem to be other levels present in ROTL which are part of packs elsewhere (example: Think Again! by Wierdy Beardy), so it does seem a bit of an unfair reason to remove them. Perhaps instead of making "exists elsewhere" a criteria fr removal, choose some limit for how many of an individual author's levels can be present. This limit can be made less arbitrary by basing it on what's needed to actually fill the pack, of course.

Just to add my own two cents to this, here are my favourite levels so far (which I'd be sad to see removed unless they're present in another pack somewhere):

NOTE: I'll update these lists later as I'm still working my way through the pack - when I do update them, I'll repost the lists for convenience.

WillLem's favourite ROTL levels

Rounds and swingabouts
Bat country
No loitering
Crystal caves
Lem dunk (a save all solution would be nice)
Brick City
Crossing The Chasm
Harder, Better, Miner, Stronger
Don't Leave Me Hanging!
Lempire State Building
Use the grey matter for this one
Think Again!
Betcha can't save just one! (a save all solution should be possible, though)
Fiery Depths
The Climbing Frame
A break in the pillar
Dilemma

And, some that I've identified as possible levels to remove:

Candidates for removal

Build it up with iron and steel - far too pixel-precise, at least in the RL version. If kept, it should be revised to allow more margin for error
Subterranean - this one look fairly ugly due to what I can only imagine are backroute-fixes which pretty much give away the solution. I'd suggest revising the backroute fixes or removing the level
Crossing Paths Part Two - not as interesting as part one, and easier. The two could swap places!

Thanks for your suggestion.

This is definitely a problem I recognise. I often find myself having to manually move pieces out of the way to get to the piece I actually want, then move the pieces back to their original position afterwards. We definitely need a solution to this, for sure.

The "select pieces below" hotkey (Alt + LMB by default) does work some of the time, but becomes difficult or impossible to use properly when there are multiple overlaying pieces. It's here in the Hotkey Config btw, should you wish to remap it to something else (Tools > Configure Hotkeys):



We can do better than this though.

To respond to your suggestion: I'm imagining that by "layers system" you mean some way of adding pieces to a base layer, then add a new layer and add more pieces there, then another layer and add more pieces there, etc. Then, be able to switch between the layers as needed. If this is what you mean, then I'm not sure I agree that a layers system is the best way to solve this problem, as it would overcomplicate rendering and give the user more UI stuff to keep track of. It just about works for image editing, but I don't think it would be a good fit for a level editor tbh.

However, since the main concern seems to be more with being able to select a certain piece more easily, there are definitely other ways we can achieve this. So, I've re-titled the topic accordingly and we can explore the various options.

To respond to some specifics in your original post:

Quote from: roltemurto on April 03, 2026, 02:49:08 AMFor my particular problem; an option to Show/Hide Steel (like any other layer) would solve it immediately.
Steel is the only asset type that hasn't got an option to hide/show.

Good shout. I'll add Show/Hide Steel in the next update for sure.

Quote from: roltemurto on April 03, 2026, 02:49:08 AMAn option in the settings or a modifier key press; that simply allow bypassing the alpha channel when selecting, would also save me right now.

This one could be done, but then the selection rectangle becomes somewhat redundant. We'd need to wrap the solid pixels with an exact outline (think 'magic wand' selection in image editors) and have that be the selectable area: not trivial to implement by any means, and still doesn't always guarantee selectability (which is what we're trying to achieve here). It's an interesting idea, though, and could be good for piece selection in general. Maybe one to come back to later.

Quote from: roltemurto on April 03, 2026, 02:49:08 AMWhat would be a QoL update is; an actual toggle button to let the cursor prioritize and select the layer at the back/behind.

This is closer. A hotkey that allows the player to 'walk' the selection through the pieces currently under the cursor could be extremely useful. Using the cursor location as a reference, hold the hotkey, and click the LMB until the piece you want is selected. This could solve the problem entirely, and wouldn't be too difficult to implement. 'Grab lowest' and 'grab highest' could also be done.

Quote from: roltemurto on April 03, 2026, 02:49:08 AMWhat would be an even better addition; is the layer system implementation;
Currently there is no way to tell how many layers are there or which and what layers are currently on the map.
...
If there was a file list ... that would allow...

The render layers are (from lowest to highest): background, objects low, terrain (inc. steel), objects high, rulers. Each piece is then drawn to its own 'layer' within that system, ordered by index. To implement a separate 'layers' system, this framework would have to be duplicated, which could get messy very quickly.

Conversely, the "asset list" you've hinted at is an interesting idea that could work perfectly alongside what's already there. We could have a pop-up list (which can be closed or opened at any time) which simply lists every piece active in the level, in index order and with details such as location, render layer, whether it's an eraser piece, etc. Clicking a piece on the list could then select it in the level arranger (and vice versa). This could work, for sure, and would be much simpler to implement and maintain than a layers system. "Move Up", "Move Down" and "Delete" buttons could also be added for convenience.

Quote from: roltemurto on April 03, 2026, 02:49:08 AMThis also makes it impossible to clean/delete an asset that has been removed/changed from the style folder,
because there is no way to select it once the editor is restarted, the level is reloaded or simply the styles has been refreshed.

Not so. Missing pieces can be deleted by simply opening a level that contains missing pieces; the Editor will identify them, and they can then be deleted by choosing "Delete Missing Pieces" from the status bar menu. If you're not seeing the status bar message when you open a level with missing pieces, then this could be a bug. This is what you should see:



Please let me know if you do not see this message when opening a level with missing pieces. You should also see it after refreshing styles (if a piece becomes missing due to the refresh).

Quote from: roltemurto on April 03, 2026, 02:49:08 AMI hope I was able to explain the situation that I am struggling with.

Absolutely, and it's something that I too struggle with now and again. You've given me a nudge to finally do something about it!

I imagine that this error probably is fixed by the RC, in which case I'll mark this as resolved but will keep the topic open in case it does come up again.

Currently, the only thing that's drawn to a higher layer than the lemmings themselves is the lemming "effects" (such as the Timebomber countdown, portal warp, balloon pop, freezing/unfreezing overlays, etc)

The layers are structured like this, from soonest -> latest in draw order:

  TRenderLayer = (rlBackground,
                  rlDecorations,
                  rlGadgetsLow,
                  rlShadowsLow,
                  rlTerrain,
                  rlLemmingsLow,
                  rlOnTerrainGadgets,
                  rlOneWayArrows,
                  rlGadgetsHigh,
                  rlTriggers,
                  rlShadowsHigh,
                  rlObjectHelpers,
                  rlParticles,
                  rlLemmingsHigh, <--- vast majority of lemming states are drawn here
                  rlEffects); <--- effects are drawn here

To achieve what you're suggesting, we could allow paint gadgets to be drawn to the "Effects" layer, but there are 2 potential issues with this, both of which add what I would consider to be undue complexity:

1) Existing lemming effects may still be drawn above the paint gadget. There may be a way to ensure that this doesn't happen, but it isn't a gimme.

2) Perhaps more importantly, we'd be introducing a way to potentially hide lemmings from the player. The community in general is already fairly prickly when it comes to hiding things like traps, exits and steel. Even speaking as someone who doesn't mind the odd hidden object now and again, hiding the lemmings is definitely a step too far. I do realise that this isn't what you're suggesting, and I can imagine that the effect you've described could look very cool. But, to avoid controversy, we'd have to implement some way to "reveal" the lemming when the cursor is over them, which adds further complexity to the feature. The more complex the feature, the more prone it is to bugs and the more justification it needs.

Then again, with all that said, I do like the idea you've suggested and I'd be interested to see if it could be made to work. If it isn't too problematic to set up, I personally wouldn't mind allowing paint objects to be drawn to the Effects layer. The only thing I'll rule out for definite is adding another rendering layer just to support this very niche feature. The rendering is already stretched pretty far as it is in SuperLemmix (given the 32-bit platform), so anything we can do to reduce the load is desirable.

Let me look into it and see what's possible.

Quote from: roltemurto on April 02, 2026, 03:49:02 AMI took a while for me to realize that you moved this under a separate topic, I thought I hallucinated reporting it  . Sorry about that.

Haha! Apologies, it's just easier to keep track of these things when they have separate topics.

Quote from: roltemurto on April 02, 2026, 03:49:02 AMI'm deleting the file now to see what new errors it'll fill up with.

Thanks for posting the full Error logs, some of those will no doubt be from before the previous "ToUpperInvariant" fix.

It would be helpful if you could clear the logs, then generate the settings error, and post just what comes up from that error.

From what you posted above, it seems to be a null reference exception when attempting to read settings. However, this doesn't tell us why the error occurred. Your settings file is clearly there, and the Editor is now locale-aware (although, there may be more that needs to be done in this regard).

So, let's see what comes up in the log from only the settings error. And, something to check in the meantime: is your settings file being saved to the "settings" folder in your SLX directory when it gets regenerated?

If nothing useful comes up in the log, I'll expand the error reporting to try and pinpoint exactly what's causing the null reference. But, let's completely exhaust the existing system first.

In reply to some of Mobius' earlier comments. Given that he's been maintaining ROTL for many years, his word on the subject and experience working with this particular bunch of levels is invaluable and should be treated as such.

Quote from: mobius on March 28, 2026, 02:51:52 PMI already have a folder of levels, some finished, some not that could possibly work here.

Great stuff, we can certainly add these to the pool if you want to share them. We will most likely need backups and replacements, as well as contributions to Assemble.

Quote from: mobius on March 28, 2026, 02:51:52 PMI do have a week off presently that I will have some time to re-familiarize myself with ROTL and maybe offer some feedback and thoughts on ROTL in general. I do have some idea of the age of most of the levels.

Any wisdom you can contribute regarding the ROTL levels will be much appreciated, especially with regards to ordering and chronology. I imagine we'll aim to structure the packs at least somewhat by age, but also taking the 2022 ordering into account.

Quote from: mobius on March 28, 2026, 02:51:52 PMset a goal for WAY fewer levels than ROTL had/has. Trust me that was too much work Like around 100 or fewer levels would probably be best.

We're thinking 120 per pack at a maximum, but I'd be open to reducing this total to 100 if it does feel like there are too many levels even with 120. Currently, given Proxima's stats and the availability of levels in general, it might be a struggle to get it down to even 120. I'm hoping you might be able to help with that if you have any ideas as to what might be able to be dropped at this stage.

Quote from: mobius on March 28, 2026, 02:51:52 PMI'd also recommend starting something totally new that has little or nothing to do with ROTL [other than being like a sequel as it seems you already may have in mind].

I know what you mean here. In fact, I originally did come up with the idea of Assemble as a separate pack intended to continue the general idea of ROTL as a 'community collab' only in spirit. But, there seems to be a general consensus (yourself included) that ROTL has gotten a bit out of hand and gone beyond its original scope somewhat, so I figured we could make a trilogy of it and restructure the original pack to be smaller.

Quote from: mobius on March 28, 2026, 02:51:52 PMMy addition of newer levels seems a bad idea in hindsight.

I won't hear of it! It's totally natural to want to add more levels to a project like this, and you did the right thing in carrying it on. I'd say the only thing that probably should have happened sooner is a sequel pack, but I imagine that the idea simply mustn't have been suggested, or maybe there was pressure to include people's levels in the existing pack? Whatever the reason, we have an opportunity to sort that out now so let's go for it.

Quote from: mobius on March 28, 2026, 02:51:52 PMwhen dealing with ROTL you're dealing with levels by people who aren't here to answer "is this a backroute or not" ... it would be far better and easier today to make a pack based on people that are here and can address questions and issues with there levels in real time.

Agreed, and we'll of course do that with the new levels. With the older levels, there comes a point where a level is what it is, and probably shouldn't be backroute fixed any further, even if the intended solution is known and the level has been previously fixed.

With that said, we have kaywhyn and Proxima on this project who are both excellent solvers and great at finding alternative solutions, backroutes, etc. We also have your specific knowledge of individual levels, which can and should be taken into account. I suggest that we fix any backroutes that we know of this time around, and then sign the pack off as final. That is, IMO we shouldn't go back and fix it later, even if something else is found. The older levels will then exist as snapshots, and we can move forward with the newer ones.

Quote from: mobius on March 28, 2026, 02:51:52 PMAlso it would be nice to utilize the new skills and features of modern games [which the old levels obviously don't have].

This is a tricky one, and will likely come up more when we come to work on the new levels. My current thoughts are that the collab packs should feel like spiritual successors to Lemmings and Oh No! More Lemmings - OG styles, classic 8 skills, etc. We all make levels in those styles, and it's good to have a collection of the best the Forum has to offer that feels like an OG Lemmings sequel.

It's also worth noting that RetroLemmini can only support the OG objects and classic 8 skills. It feels right to have the community collab be something that is compatible with both platforms (NL and RL), but then I am biased as current RL dev! Other people's opinions on this will be needed later, no doubt.

Quote from: mobius on March 28, 2026, 02:51:52 PMpart of why I got frustrated with the project was that besides the end result being too large lots of people came in saying they wanted to contribute but in the end I did most of the work

Yes, this needs to be addressed. Everyone who's contributing has taken on clear roles, these:

Proxima - Level selection and ordering, general presentation
kaywhyn - Solving and backroute-fixing, managing feedback
Me - porting to RetroLemmini, music selection and ordering, general presentation

There will be more to delegate as time goes on, and we'll all be involved in all parts of the project ultimately, but having people in charge of different things will hopefully make it so that no single person feels it's all up to them to do everything.

As far as yourself goes, you're welcome to be involved in whatever capacity you wish. We will most likely need you for a bit of everything, given your experience with the levels, but there's honestly no pressure for you to do anything in particular. You've already done enough getting us this far!

Quote from: mobius on March 28, 2026, 02:51:52 PMand there were generally only a few people coming forward with opinions that disagreed, so they ended up at an impasse.

This is also a concern, especially given how quickly Forum discussion can dry up. But, I'm confident that we should be able to tackle most decisions as long as we remain invested. A decision-making process will likely present itself as we go on, I imagine, and - if it doesn't - I have several methods and techniques to help with this that I use for my own projects, and they work to just get things done. We can use those if needed.

Quote from: mobius on March 30, 2026, 05:51:02 PMJust to quickly add; in case I didn't mention this before; every time I produced an update; my biggest concern was taking in everyone's feedback.

Thanks for the heads up on this. I'd suggest that we treat existing feedback on the original levels as final, and go with our own individual opinions when it comes to sorting these levels out. For new levels, these will likely require a fresh process of releasing levels, taking on feedback, etc. I'll try to think of the best way to go about this given the current Forum setup. We'll likely hit Discord a lot for this.

Quote from: mobius on March 30, 2026, 05:51:02 PMI fully support whatever you guys do with this. If we start a new pack (sequel or whatever) I'd recommend making a new topic for that, inviting people to post levels and go through a playtesting period, like we did with the lix community set. That was tons of fun honestly, I hope we can do that again, even if my involvement is minimal.

Glad to have your approval, that means a lot. I hope that you can be involved in the new collab pack without the pressure of having to maintain it!

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Quote from: mobius on April 02, 2026, 12:39:09 AMin case any levels by ISteve are being used; The Top Shelf; all these are ruined by instant bombers ... if the levels are adjusted then it wouldn't matter reinstituting a timed bomber.

Thanks for clarifying this, mobius.

I'm pretty sure we've opted not to include levels by Insane Steve that are duplicates from his main level pack (although this decision isn't by any means final yet), so this may not be an issue anyway, but good to know just in case this particular level is ROTL-exclusive.

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Quote from: Proxima on April 01, 2026, 11:34:34 PMstill leaves 287
...
So the process of splitting the pack will also be a selection process -- some levels won't make the cut any more.

Easier repeats are another gimme. Any stats on the level count once these are removed?

Also, are any other levels featured in other packs, or is it just the ones from Mazu, Insane Steve and Clam?

Quote from: Proxima on April 01, 2026, 11:34:34 PMlevels will need to work on both engines, and I'm not sure exactly what set of features are available in RL.

At a very quick glance:

NL/RL shared level properties

Max level size: 3200 x 3200
Release Rate: 1-99 (locked RR supported)
Time limits (<= 99 minutes, infinite time supported)
Max lem count: 999
Normal lems only (no zombies or neutrals)
Classic 8 skillset only (<=99 thereof, infinite skills supported)

Available objects:

Fire
Water
Continuous traps (i.e. one-shot is not supported)
One-Way-Arrows (all directions are supported)
Force field left/right (essentially the Blocker effect)

One important difference: RetroLemmini supports optional Timed Bombers. Levels which feature the Bomber skill should ideally not require the skill to be used within the first 5 seconds of the first lem spawning. Should this come up, the ported level may need a small layout tweak to ensure that the standard solution is still possible with Timed Bombers.

Other physics differences are likely to be insignificant, or easy to handle when porting.

Quote from: Proxima on April 01, 2026, 11:34:34 PMthe first two packs will use only the originals plus a handful of L2 styles, so it might be good to do the same in the third pack for consistency.

Strongly agreed. This project should only feature OG / L2 styles ideally. Level contributions using other sets should be remade, wherever possible.

Important note: RetroLemmini does support tileset mixing, so if a level uses mixed styles it can be ported.

Quote from: Proxima on April 01, 2026, 11:34:34 PMWell, we are producing a new version, so ... this will be version 5.

Sure, but we're working from version 4.0 - that's significant, and should be understood by all concerned. Also, this project is intended to replace v4.0, not follow it. I'll make that clearer in the above post.

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