He's also posted the full interview with Scott Johnston.

Quote from: hrb264 on February 28, 2026, 09:24:04 AMIs it OK to leave it in Mayhem as a kind of 'breather'?

Yes. It's your pack, go with your instincts

Quote from: hrb264 on February 28, 2026, 10:49:49 AMI get the impression many people often like to have 1 or 2 of each skill and don't like this sort of level? (To be honest, 1 of everything levels aren't my favourite type )

Mine neither, I'm also a fan of more open-ended levels that provide enough skills to find more than one solution. To each their own.

Don't try too hard to please others. Make the levels you'd want to play yourself.

Also I usually like to be quite generous with the skill set because I often make mistakes  especially if I make levels with 100+ lemmings, or where you have to assign a load of floaters etc, but I get the impression many people often like to have 1 or 2 of each skill and don't like this sort of level? (To be honest, 1 of everything levels aren't my favourite type )

Thanks very much both

So I made a repeating level that gets harder, I finished the 'mayhem' version of the level which I was intending to be hard, it's definitely more difficult than the previous ones but I don't think it's as hard as my other levels in that rank and is probably a difficult 'taxing' level? Is it OK to leave it in Mayhem as a kind of 'breather'?

 

I've now implemented a failsafe for replays made in SuperLemmini versions 0.103 - 0.104a (which have untimed bombers only). Previously, if the "timed/untimed" data was missing from the replay, RetroLemmini would fallback to user option. Now, any replay made in these specific versions will be assumed to have untimed bombers.

Unfortunately, there's no way to account for replays made in SuperLemminiToo because this is when the timed bomber option was first made available but wasn't yet written into the replay (that came about in RetroLemmini 1.0). However, it is still possible to fix these replays manually should anyone wish to do so:

How to fix SuperLemminiToo replays which include Bombers

1) Open the replay in a text editor.
2) Find any line which matches the following:
   n, 2, FLAPPER, lem   (where "n" is the frame number and "lem" is the lemming index)
3) If the replay was made with the Timed Bomber option enabled, type ", true" at the end of the line. Otherwise, type ", false". Examples:
   162, 2, FLAPPER, 0, false   (an untimed bomber assigned to lemming 0 at frame 162)
   394, 2, FLAPPER, 5, true   (a timed bomber assigned to lemming 5 at frame 394)

Done!

Implemented in RLPlayer commit 14affaf.

OK, made a little bit of progress with this today.

Out-of-bounds exceptions for lemming indices are now handled by displaying the expected vs. actual lemming index in the window caption, like this:


So, the replay has an action for lemming 11, but there are currently only lemmings 0-5 available in the level.

Also, when loading a replay, RetroLemmini falls back to matching by level name alone if it can't find an exact match for pack title, rating and level name (this has been in effect since 2.7). This does occasionally result in mismatched replays being played, so let's show the expected name + pack title in the caption. The purpose of this is to make it easier to see which level the replay is actually for:


The replay is for "Take A Running Jump" from Lemmings, But With Lemminas!. This pack can't be found, so RetroLemmini has loaded "Take A Running Jump" from regular Lemmings.

Whilst there's still no guarantee that the replay will play without issues, the above tweaks at least help matters by reducing unhandled exception popups, whilst providing better user feedback so that issues can be more easily identified and fixed.

Meanwhile, I'll keep looking into what can be done to increase backwards compatibility with older replays.

A question as old as custom lemmings levels, this one.

The difficulty of custom levels (as Proxima has already pointed out) is greater than that of the original games, but if we stretch the graph so that Fun still means "as easy as the game can be" and Mayhem still means "as difficult as the game can be", the following questions can provide a good barometer to sort levels out:

1) Does the level expect the player to find a single intended solution? Yes = 1, No = 0
   1b) Is the level a tutorial level, or a level where the solution is intended to be obvious? Yes = -1, No = 0
2) Does the skillset provide more skills than are required to solve the level as intended? Yes = 0, No = 1
3) Is the layout of the level specifically tailored towards patching out all other possible solutions than the intended one? Yes = 2, No = 0
4) Does the level's intended solution feature a specific trick that the player must know/discover in order to find the solution? Yes = 3, No = 0
5) Once the solution is known, how easy* is it to play the level in real time without using the pause button? Easy = 0, Not easy = 1
6) Are there any assignments which cannot be made without the use of the pause button, L/R arrows, or any other player assists such as framestepping or skill shadows? Yes = 2, No = 0

*For the purposes of this question, if the level provides little to no challenge when playing out the known solution in real time, it's "Easy". If executing the solution presents any significant challenge at all during real-time play, it can be scored as "Not easy".

If the level scores more than 0, it's probably at least Tricky difficulty. The higher the score, the more likely it is to be Taxing or Mayhem, keeping in mind that the highest possible score from the questions above is 10.

The questions matter in combination as well. For example, if questions 1, 2 and 3 all score positively, I'd say it's at least Taxing if not Mayhem. If questions 1 and 4 score positively, but 2 and 3 score 0, it could be a more difficult Taxing level or even a Tricky level depending on how lenient the skillset is.

Really, measuring difficulty is a learn-by-doing process. The more levels you make, and the more solutions to your own levels by other players that you see, the better an idea you'll have of how difficult your level is.

As a player, I always appreciate it when a pack starts off with a bunch of easy, open-ended levels just to get me going. It's a good way to get to know the author's level design style and get warmed up for the later levels. Like a professional piano player doing a few scales or playing a few easier pieces to warm up before a concert, I see it as a necessary part of the process.

Anyways, keep going, keep creating. That's the best way to learn.

Quote from: Airwave on February 27, 2026, 11:07:07 PMI'm new to the forum but I've been playing Lemmings on and off since the 90s. I got back into it in the last few month when I discovered RetroLemmini and have been playing a lot lately.

Welcome to the Forums! Glad you're enjoying RetroLemmini

I've replied to the replay concerns here.

Thanks for reporting

Quote from: Airwave on February 27, 2026, 11:07:07 PMWhile writing this I just discovered the replay with 17 saved, which I recorded in version 2.7, doesn't work correctly in 2.8 and becomes unsynchronised.

I'm unsure why this is happening. The level itself and the game physics are both identical between 2.7 and 2.8, so this desync bug is fairly concerning. We'll see if it happens with any other levels/replays.

Quote from: Airwave on February 27, 2026, 11:07:07 PMIt turns out the recording in 2.8 crashes while playing in 2.7.

This one's an out-of-bounds exception, these are unfortunately quite common in the Lemmini codebase. I'm working on better error reporting so that we see something like "there are fewer lemmings than expected" rather than a generic error, but it's a one-at-a-time kind of process.

Quote from: Airwave on February 27, 2026, 11:07:07 PMIt seems all other replays are fine when played in 2.7 and 2.8 so I can only assume that glitch causes problems with replays.

It's possible, but the expectation is that all replays should be cross-compatible between all RL versions after 2.6, which was the last time physics was updated.

Quote from: Airwave on February 27, 2026, 11:07:07 PMI noticed the replays in this thread from 2021 don't work in RetroLemmini.

I think I know why this is. The Flow Control replays from 2021 that you're referring to were created in SuperLemmini 0.104, which didn't have timed bombers. If you play back the replays with timed bombers enabled, the actions will desync. If you disable timed bombers and then load the same replays, they play back as expected. RetroLemmini has fixed this for newly-created replays (any replay made since RetroLemmini 1.0 accounts for the timed bomber option in the replay), but it may be worth implementing a failsafe if a 0.104 replay is detected - in this case, RetroLemmini should assume untimed bombers rather than defaulting to user option. <--- EDIT - this has now been implemented.

Incidentally, versions 2.7 and 2.8 both report on replay compatibility in the window caption. When you play back a replay, it may show something like this:



The above indicates that the current RL version is 2.8, the compatibility version is 2.6, and the replay version is 0.104. "Compatibility version" refers to the last physics update, so the general expectation is that replays made since that version should play flawlessly in the current version. The replay version is 0.104, which is well before 2.6, so there's a chance of errors occurring during playback.

I'll look into it and see if there's more that can be done to increase backwards-compatibility, or at least better error feedback.