Users can now set Insert as the default mode (NLCEPlayer commit 2f55cf7.)

This means that as soon as a replay begins, it will do so in R Insert Mode (if that's the desired default mode) rather than R Standard Mode. The 'Insert Mode' toggle hotkey (O by default) can still switch between the two as usual.

So, we can now tweak Insert Mode to be more like the proposed 'Single Mode' (which we can now consider rejected as a standalone idea), and advanced users can set this as their default mode if they wish to do so.

I believe this solution offers the best of all worlds.

Solved the Bittersweet levels. Another high quality batch, and these are getting tough now!

OK... guarding against re-entrancy didn't work (although I still can't shake the suspicion that this is what's responsible, albeit maybe from the Windows side).

I'll make an exerimental build that logs clicks and ask Flopsy to test it, but... thinking about it, I'm beginning to wonder if it's time to just re-think the entire Level Select menu.

I'd like to set the treeview on fire and display the levels some other way.

Lix is able to search 1000+ levels in seconds. How does Lix store levels in the menu? Does it cache on load? Does it store them as a simple list and worry about connecting the level to data later, or is storage fully object-based?

The fact that Lix lists the levels on buttons is clever; the buttons cannot be clicked twice, which is an elegant way to prevent having to re-load the same level.

Added a Nuke status check to the second block. This fixes the bug but keeps the pre-assigned check available should it prove to be necessary for any reason.

Fixed in NLCEPlayer commit 636fdeb.

Thanks for the heads up and the suggested fix.

Just to double check, you are referring to the second block in CheckIfZombiesRemain?

function TLemmingGame.CheckIfZombiesRemain: Boolean;
var
  i: Integer;
  ReleaseOffset: Integer;
begin
  Result := True;

  for i := 0 to LemmingList.Count-1 do
    if LemmingList[i].LemIsZombie and not LemmingList[i].LemRemoved then
      Exit;

=============== FROM HERE =================

  ReleaseOffset := 0;
  if (LemmingsToRelease - ReleaseOffset > 0) then
  begin
    i := Level.Info.SpawnOrder[Level.Info.LemmingsCount - Level.PreplacedLemmings.Count - LemmingsToRelease + ReleaseOffset];
    if i >= 0 then
      if Gadgets[i].IsPreassignedZombie then
        Exit;
  end;

============== TO HERE ==============

  Result := False;
end;

Removing the second block fixes the bug, but just wanted to make sure that's exactly what you meant.

Quote from: Proxima on August 24, 2026, 02:06:39 AMThere is no such thing as cheating in a single-player game

Fair enough. A better way to put it is probably "it undermines a big part of the game's challenge", which - in the case of L1/L2/L3 - was to solve the levels in real-time as much as possible as well as solve the puzzles.

Quote from: Proxima on August 24, 2026, 02:06:39 AM

QuoteWe all agree that the ability to framestep backwards immediately renders most of the original levels (which is what many players come to the Forums looking for) obsolete.

Out of 120 levels, there are five timed bomber levels in the entire game. ONML has only two out of 100.

Did I miss something? We're not talking about timed bombers here, we're talking about framestepping. The original point stands: a lot of L1 levels feature challenges related to general timing and crowd control, which are rendered trivial by the ability to framestep.

Quote from: Proxima on August 24, 2026, 02:06:39 AMIt's true that the original game didn't have any kind of replay system ... if it had had replays from the beginning, I can't see that anything I liked about the game would have been changed or diminished.
...
And then UU got added, nothing really changed, and it was still the same game, just easier to play.

Fair enough. There's a very good chance that adding the ability to jump backwards a bit (possibly via savestate loading) won't ruin RetroLemmini's general gameplay and will just save the player time, which is an important consideration and the reason for this topic in the first place.

Any Rewind feature will no doubt be a balancing act between making the game better to play, and retaining as much of the old school 'charm' as possible.

Quote from: Proxima on August 24, 2026, 02:06:39 AMI know that maybe it's not my place to say these things ... I'm mostly contributing because I hope this discussion can help you reason out the decision

This is much appreciated. All feedback is good, all opinions are valid and helpful to the outcome one way or another. Thank you for taking the time to contribute your thoughts!

Quote from: Simon on August 23, 2026, 11:38:59 PMDebugging idea

Thanks for the ideas

For now, I've guarded against re-entrancy for treeview and preview loading, both of which are relatively expensive tasks. They've already been fairly well optimized, but I realised that there's nothing actually preventing them from being called multiple times. Multiple quick-succession clicks would be a problem, then.

The re-entrancy guard should hopefully do it. Flopsy is testing now.

Caching is a very good idea, but... it would need to perform a cache every time it opens/closes to keep it up to date (potentially?).

Jingles or other sound effects can help. Fireworks/party streamers/ticker tape/confetti. 'CONGRATULATIONS!' in big green letters. A Lix holding a trophy for a win. A Lix crying for a loss

Quote from: Simon on August 23, 2026, 09:24:47 PMLemmings 3 happens to implement what you're considering. Solutions from an action replay don't count ("learner mode") for progression. Feature is meticulously implemented, but you're not supposed to use it until you've proven your worth. Reaction by Kieran:

Quote from: kieranmillar on July 17, 2023, 10:54:20 PMusing the replay feature makes the solve not count (why oh why did they do this? Idiots)

They did this because using the replay system to solve a level was probably considered cheating (or at least contradictory to the spirit of the game as it was intended to be played) by the developers. Otherwise, of course they wouldn't have implemented it in this way.

Part of the original challenge of Lemmings was to be able to solve the level in one single playthrough. If you could do that, you'd beaten the level good and proper, fair and square. And, of course you could pause the level to take a moment to set up your next action, but all assignments had to be made in real-time: that was a legitimate and enjoyable part of the challenge. I can't be the only player that thinks like this.

Anyway, RetroLemmini has already sacrificed some of this by having a replay system. So did Windows '95 Lemmings (which also allowed assign-whilst-paused). And yet, it never felt like it was getting in the way or completely ruining that aspect of the game because it wasn't used for fine-tweaking.

Most of the time when playing in RetroLemmini (which is currently my preferrd engine for actually playing Lemmings), I click to cancel my previous replay because I want to mostly do the solution over and don't care about sacrificing a few assignments; a fresh start is preferable. Again, I cannot be the only player who thinks like this.

Conversely - when I'm playing in NeoLemmix/Lix, I use backwards framestepping, of course - why wouldn't I. But, it makes the game feel totally different. Specifically: there are no real-time stakes at all. Nothing I do really matters because I can just skip back and redo it immediately. It feels like I'm editing a video clip rather than playing a video game. This is fundamentally a different way to play, and it matters.

Is that closer to the holistic argument you were hoping for? I'd be happy to unpack my thoughts on this further. And make no mistake: I would never want the player assists to be removed from Lix, NeoLemmix or even SuperLemmix. I just want to be very careful about adding them to RetroLemmini.

Flopsy has reported that this bug is still present in NLCE.

Help welcome.

Looking at the video again, this is a repeat of this bug in SuperLemmix. I never did figure out exactly what was causing it because it's impossible to test for. It happens randomly, and there are no definite steps that will cause it to happen. I can click many times in the Level Select menu and not duplicate the reported behaviour.

So, unless anyone has any debugging suggestions, this might be another one we just have to live with.

Quote from: Simon on August 23, 2026, 07:20:26 PMIf this means backward and forward skips (+1/−1 physics update, staying paused): You'll have to remove some cheating features from RetroLemmini. As-is, you can click to advance by 1 physics update during pause.

Yes, as I said, it's unfortunate that this is already a part of RL. It won't be getting removed, but it has been made optional by another user/developer (Charles) who seemed to have a similar opinion.

Quote from: Simon on August 23, 2026, 07:20:26 PMthe difference between cheating and not cheating ... is drudgework. This is Mindless's "It's just tedious, and that doesn't make for a good game."

Hm. Maybe I disagree that it doesn't make for a good game. If that's true, why are we all here? The vast majority of original Lemmings ports don't even have a replay system, let alone per-frame control over the gameplay. It can't be that bad a game if there's an entire Forum dedicated to it...

Quote from: Simon on August 23, 2026, 07:20:26 PMYou can design the game like this. But is that good?

Maybe this is a question to which I don't think the answer should automatically be "no". If the player is punished for making a mistake, the real-time gameplay stakes are higher. Some players genuinely enjoy this. Lemmings itself was more or less built on this very principle.

And yes, it has evolved - and that's good. But, we have engines with player assists which we all (myself included) enjoy; we should also have one that presents the more traditional gameplay style.

Quote from: Simon on August 23, 2026, 07:20:26 PMDon't punish/lock X, instead reward Y.

Reward pause-free playing.

Yes, this could work. The Talisman system in Neo/Super is good; both players and designers benefit from it. I thought about implementing a challenge/trophy system in RL but realised how complicated it would make everything and so abandoned it (for now). I think it would only be worth the effort if it were a somewhat online feature, where players could see which trophies they (and other players) had achieved.

Counter-point, though: offering 'modern' features after a successful 'classic' playthrough is 'reward' rather than 'punish', is it not? We're saying: "well done, you completed the level without player assists, now they're unlocked for this level". Maybe it is a bad idea, I'm not 100% convinced of it myself. I'm just exploring the possibilities at the moment.

Quote from: Proxima on August 23, 2026, 05:53:28 PMIf the purpose of adding a feature is to improve quality of life, then it should not be locked.

Admittedly, I'm struggling to think of examples of games that provide QOL features as rewards, but I'm sure they do exist. One that springs to mind is Super Mario Sunshine, which allows the player to use Fludd on subsequent plays of the 'platforming challenge' levels once the main quest is completed. In this context, Fludd can absolutely be seen as a QOL feature, because it makes these levels significantly easier to traverse.

I'll come back later with better examples.

Quote from: Proxima on August 23, 2026, 05:53:28 PMYou wouldn't have attempted it if it were impossible.

Have you met me?? Attempting the impossible is my jam!

Quote from: Proxima on August 23, 2026, 05:53:28 PMAre you going to set up a vetting system so that levels by other designers must pass this threshold before they're allowed to be published?

Definitely not. Anybody is welcome to make any levels for RetroLemmini that they wish. We could even put the decision of whether or not to lock the player-assists in the hands of the level designer. I did originally think that, and now regret not including that detail in the idea suggestion.

My 'standards' are not so unique, either; they reflect the strong opinions of other Lemmings players. However small, there will always be a group of players who want the game to be presented more or less as it was originally. RetroLemmini is for that group.

Quote from: Proxima on August 23, 2026, 05:53:28 PMlevels that don't meet your standards will continue to be made, and "I'd rather they didn't get made" isn't a good answer to the question of whether the engine should have better quality-of-life features.

I never said I'd rather those levels didn't get made. This is more a question of which gameplay style we want to support than a comment on level design (the original levels are, of course, an exception to this because they are the original levels, and this Forum wouldn't exist without them).

I should probably take issue with framestepping being described as a 'quality-of-life' feature here. Direction-select and assign-whilst-paused are arguably QOL features. Framestepping, on the other hand, is tantamount to cheating in a game like Lemmings. We all agree that the ability to framestep backwards immediately renders most of the original levels (which is what many players come to the Forums looking for) obsolete. We have to be careful not to do the same in RetroLemmini - that's the bottom line here as far as I'm concerned.

Quote from: Proxima on August 23, 2026, 05:03:53 PMThis seems like very much a "worst of both worlds". You put yourself to all the trouble of coding the feature and you prevent the player from using it. What's the point?

It's basically a reward system (many games lock features behind progress - this is normal), and one which specifically says 'we want you to solve the level without using framestepping', which - let's be really clear about it - is what we're aiming for here. Other player-assists could be encompassed here as well, although I'd probably draw the line at just framestepping; even Windows '95 Lemmings has assign-whilst-paused and direction select.

Quote from: Proxima on August 23, 2026, 05:03:53 PMThere is, of course, no such thing as a level that requires framestepping shenanigans...

The first Lemminas pack and (particularly) Lemmings Recurring both feature levels which are basically impossible to complete in real-time. I've tried.

After making those packs and realising that I actually disliked playing that way (and that NeoLemmix's player assist tools had made such levels possible to create and solve in the first place), I resolved to only ever create levels that can be solved without even using assign-whilst-paused. Obviously, all levels are made easier with the player assists, but when a level more or less demands that you use them, it's a bad thing (IMO).

Quote from: Proxima on August 23, 2026, 05:03:53 PManything that can be done with framestepping can be done without.

A level that requires assignments on frames X, X+2, X+4, X+6, X+8, etc. would be near enough impossible to complete without using framestepping.

Quote from: Proxima on August 23, 2026, 05:03:53 PMI think what you meant was on the lines of: "We don't want levels that are really annoying and fiddly to play without framestepping." ... what counts as "too annoying and fiddly" is hugely subjective.

You're right that opinions will differ on this. IMO, if a level requires an assignment on frame X, and another at frame X+n where n is less than about 10, it's too fiddly and annoying. Obviously, the closer to 1 n is, the more fiddly and annoying it is.

Quote from: Proxima on August 23, 2026, 05:03:53 PM

QuoteI can think of 2 possibilities

What happened to the checkpoint and jump-to-previous-skill possibilities mentioned in the first post?

I meant 2 possibilities of a Rewind system that could possibly preserve traditional gameplay (as opposed to a Rewind system in general). I've updated my previous post to reflect this, apologies for the miscommunication. At this point, all ideas being discussed in this topic are still on the table (including, of course, "do nothing").

Quote from: Proxima on August 23, 2026, 05:03:53 PMadd a savestate key

Yes, this is another possibility for sure. If anything, any Rewind system that's implemented would need to be savestate-based anyway, so this step would arrive sooner than a Rewind button anyway.

Quote from: hrb264 on August 20, 2026, 08:00:17 PMi dont think id use it and dont really like the idea but i'd probably be ok if it was added as a mode you could turn on and off

Quote from: Flopsy on August 23, 2026, 10:50:27 AMI'm still of the mindset that rewind is not needed. Just having a faster fast forward option is preferable for me.

I like that RetroLemmini preserves the classic Windows 95 Lemmings

Yes, preservation of this gameplay style should be RetroLemmini's main goal, given that the other engines/clones already provide a wealth of player assist tools to make the game easier and significantly refocus the play style.

I can think of 2 possibilities (of a Rewind system that preserves traditional gameplay style):

1) Don't add Rewind, just add a 'Nitro' fast-forward speed which can be used to blast through the replay to the desired point. This is essentially what backwards framestepping actually does, but we add it as a manual control for the player to master.

2) Add Rewind, but lock it behind a 'Modern Mode' along with forwards Framestepping (which Charles made optional in SuperLemminiToo for some of the same reasons that are being discussed here; he saw the need to preserve the traditional gameplay style). A player must complete the level at least once in 'Classic Mode' before the modern controls are unlocked for that level. The player can choose to keep them locked, if desired.

(2) is much more work. I'd prefer to go ahead with (1) for now. We can trial this in the next RetroLemmini update and see if it's sufficient enough that we don't need (2).